Experiments That's Science

8/9/2019 Experiments That's Science

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Netejar xid (p.120) objectes rovellats (claus), aigua+sab, lleixiu, cola, vinagre, suc llimona.

densitat amb xocolata (p.132)

xocolata, gots, aigua, gasosa.

Absorci bolquers (p.137)

un (o diversos) bolquers, aigua destillada, aigua normal, tisores o cutter, balana.

+Assecar-lo/estendrel?

com es fan les pastes de dents amb ratlles

pasta de dents de coloraines de diferents marques, congelador, cutter

Diferncies i similituds fibres (p.142) (cot-paper, cabell-llana)

floc de cabells, tros de cot, tros de paper, tros de llana, pinces, encenedor

Sensibilitat dels dits (receptors pressi) (p.145). PROVAT AMB 2 AGULLES DE MITJA FINES.

SHAN DE POSAR JUNTES I IMPACTAR ALHORA.dos escuradents o dos pals de fusta llargs de pinxo o de cosir filant.

Calor. Conducci trmica (p.150)

Plat de fusta i plat metllic paella i plat de plstic + 2 glaons idntics.

Turbulncia aire (p.160)

Pilota de rugbi, pilota rodona de mateix dimetre i pes semblant

Pressi aire, fluids p.166

assecador, bola ping-pong

teoria cineticomolecular (globus congelador) p.170globus, congelador, cinta mtrica

caiguda lliure p.181

full paper, manyoc de claus. ( o 2 boles de diferents materials)

funcionament extintors p.188 (NO surt massa)

ampolleta plstic, punx, canya plstic, bicarbonat, vinagre, espelmes, quelcom per encendre-les.

electrosttica:encendre fluorescent amb globus i llana (p.204) FREGAR DIRECTAMENT ELFLUORESCENT AMB LLANA JA FA LLUM, PER CAL FOSCOR ABSOLUTA (ISESCALFA). AMB EL GLOBUS S GENIAL!

fluorescent, globus, llana

Irradiaci-absorci calor en funci del color (p.206)

Multilog i cartolines? 2 vasos idntics de diferent color?

Materials intelligents p.209

Envas iogur, fog o font de foc, pinces cuina (PROVAT, NO HA SORTIT)

fluids.volar avi (efecte Bernoulli) p.211

foli

Pressi en slids. prmer un ou p.220


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ou, drap, m.

Dissoldre ou + identificar calcriaBossa amb aigua i donar volta sense que caigui

Barrejar vas ple daigua i de cendra

Empnyer els marcs de la porta amb els reversos de les mans

oxidaci dels pltans: fora, nevera, nevera amb paper, nevera amb film de plstic.

Singlot, remei xumari i mirar Dani Jimnez

Buscar bitxos amb sang blava

Fusi gel en aigua

Mescla frigorfica

Buscar tub de Rubens i explicar

Llevats en tubs dassaig + globus i sucre

Travessar globus amb punxons de fusta o agulles de mitja.

Tensi superficial: llet, colorants, sab

Cromatografia: bolis o rotuladors, alcohol, acetona.

Nvol que sinfla

Tub dassaig que desapareix (amb oli Johnsons)

Pilota de ping pong que es recupera (sumergida en aigua calent)

Happy plants angls

Pgines cincia en angls

Explorelearning.com

http://scifun.chem.wisc.edu/HomeExpts/HOMEEXPTS.HTML

Experiments en angls


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Experience one: two spray ........................ (one with water and the other with alcohol) and somethingto put over the eyes and nose in order not to .......................... or smell. (.......................).

Put the ........................ over the eyes and nose of a voluntary. Spray at the same time the same amount

of alcohol and water over the ................................., and ask him/her wheres the ........................... Its

easy to know because of the cold sensation when it evaporates. It happens because alcohol is more

volatile than water, so it gets the warmth of the skin producing a decrease in temperature.

Volatility depends on the strength between molecules, so molecules of .................... are joined by a

bigger strength than the alcohol ones.

Activities

1. Fill the gaps in the text.

2. Mark the comparative sentences.

3. Look for the boiling point of water, alcohol and acetone. Copy them next to the word and

put the three substances in order of increasing volatility.

Acetone:

Alcohol:

Water:

4. Complete the sentence:

To evaporate a substance, we have to give it ..............................

5. Make a drawing of the expierence writing the main things which are needed.


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Experience two: balloon, metric sewing belt, ............................

We fill a balloon with air and we measure the width with a ............................................ We introduce it

in the freezer at -20C, and we take de measure again after some days.

Kinetic Theory explains this effect by the movement of the gas molecules: when it gets

very ......................, molecules move more slowly than at .............................. temperatures. For this

reason, they collide less times against the balloon walls, and this means less pressure.

Activities

1.Fill the gaps in the text.

2. Mark the comparative sentences.

3. Explain with your words the opposite effect: what happens to a balloon when it is heated.

4.Translate (use the dictionary):

Heat:

Hot:

Warmth:

Warm:

Cool:

Cold:



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Experience three: plastic glass, felt-tip pen, ice cube, water.

Put water into a plastic glass (more than a half). Add an ice cube and make a line on the glass with the

felt-tip pen where you see the water level.

1.Prediction: Where will be the water level after the ice cube melts? (Mark your answer).

- Below the line.

- At the same line.- Above the line.

2.Observation: Wheres the water line when ice cube melts?................................................................ .

3.Explanation: (take notes of the explanation in catalan).

4.Translate the explanation:

This is the same phenomenon when an iceberg melts. We have to be worried about the continental ice,

because is the real ice which is able to increase the sea water level (Greenland, the Antartic...).

5. Make a drawing about the experience, with two glasses: one before the ice melts and another oneafter it melts. Write the main things that are needed.


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Experience four: broken ice, salt, thermometer, test tube, colouring, water.

Put into a glass four parts of ice and a part of salt (200g and 50g, as an example). Mix it. Put water into

a test tube with a little of colouring. Look the temperature into de tube and write

it: ...................................

Look the temperature of the ice and salt mixture and write it.................................

After that, put the tube into de mixture and wait for several minutes. See how the tube looks like, andmeasure the temperature in the end:.............................

When we throw salt on a snowy floor this has two functions: salt has a high hygroscopic capability; for

this reason it melts snow. Moreover, it decreases the melting point, so weather has to go several

degrees under 0C to become water to ice.

1. Translate the last three sentences.



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Experience five: onions, water, plastic knives, swimming glasses.

Each pupil cuts the half of an onion in very little pieces. Look each other: who is crying?

The ones that cut the ....................... in water or wearing .................................................

dont ....................

When we cut an onion its been produced a substance calledsyn-propanotial-S-oxide which, with

water, reacts producing sulfuric and sulfhidric acid that irritate the cornea. The lachrymal producestears in order to remove the acid from the eyes.

Activities1. Fill the gaps.

2. Why if we cut the onion in water it doesnt make us cry?

3. Why if we cut the onion wearing swimming glasses we dont cry?

4. Search in the web for a drawing of the eye structure with the name of the different parts.


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Experience six: rusty objects, glasses and different household liquids.

We prepare five glasses with the same amount

of ......................................................................................................................................................... .

After that, we introduce the rusty objects and wait for some days (or a week).

As time goes on, the rust of some of the objects is easily removed.

Activities:

1. Translate the name of the substances in the glasses:

Glass 1 glass 2 glass 3 glass 4 glass 5

Aigua amb sab vinagre lleixiu coca-cola suc de llimona

---------------------- --------------- ------------- ------------- ----------------------

2. Fill the big gap on the top.

3. What are the substances which are able to remove rust?

4. Whats the property that this substances have to do it?

5. Complete the sentence:

................................... substances are good rusty removers. Otherwise, the basic ones (the

opposite property) are good ............................. removers.


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Experience seven: metallic dish, plastic dish, two ice cubes.

Put each ice cube on a dish. Wait several minutes and write what happens:...................................................................................................................................................................

..................................................................................................................................................................

Air is a good thermal isolator, and is sorrounding five of the six sides of each ice cube. We find the

main difference in the bottom side, because of the thermal conductivity of each substance.

Activities1. Complete the sentences withgood/bad:

Plastic is a .......................... thermal conductor.

Metals are ................................... thermal conductors.

2. Write the comparative sentence using better.

3. Write the comparative sentence using worse.

4. Why do you think that many times we put plastic plates in the buildings between the walls?


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Experience eight: two bottles, a bit of paper, (hotter/heater), (freezer/fridge), colouring.

Fill one bottle with water about three quarters and introduce it in the (freezer/fridge). (Heat/hot)water and fill the other bottle about three quarters with the (heat/hot) water.

Put the colouring into the bottle with the (heat/hot) water. Then, join the two bottles by its tops

upside down with a little bit of paper between them, with the hot one on the table.

After that, take the paper out and look what happens. Write it:

.....................................................................................................................................................................

....................................................................................................................................................................

(Hot/heat) water is less dense than (cool/cold) water and goes (up/down), moving the (cool/cold)

water too.

This is the reason why currents are created in lakes and sea. The same reason why big amounts of

air move. The same movement of magma in asthenosphere (convection currents). And this explains

why aerostatic balloons can fly.

Activities

1. Choose the correct option in the words in brackets.2. Make a drawing of the two bottles joined writing the main things of the experience


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3. Rewrite the explanation with the correct options.

Experience nine : two cardboard ashtrays, heater, water, chronometer, tongs.

Put an empty ashtray above the flame and count the time until it burns. Time:...............

Then, fill the other ashtray with water and do the same. Time:..................Explain why do you

think this happen

Experience ten: egg, hand, rag (just in case), balloon, needle

Catch the egg by the opposite sides (top and bottom) with two fingers: thumb and forefinger. Press

with all your strenght. What

happens?.........................................................................................................

Egg shape is perfect to distribute the strenght in all directions so it (not

break)............................................... .

You can also try to do the same with the egg lying on your hand. Close the hand slowly pressing the

egg and dont make an special strenght anywhere with the fingers.What

happens?................................................... .

Now blow up a balloon to a middle size and try to pierce it by its soft zones (bottom to top). Its very

difficult to do, but its the only way because in those places rubber has not exceeded its elastic limit.

Activities

1. Fill the gaps.2. Search for the main compound in the eggs shell. Write

here:.............................................................

3. Make two drawings: one for the first situation an other one for the third one.


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Experience eleven some different stones, hydrochloric acid (HCl), glass, egg, vinegar.

We will try to identify calcareous stones (rich in calcium carbonate, CaCO 3).

Throw some drops of hydrochloric acid solution to each stone.Write what happens:

Stone 1 Stone 2 Stone 3 Stone 4

................................... ................................. ................................. ...................................

When ......................................... reacts with ............................................... two chained reactionshappen:

HCl + CaCO3 CaCl2 + H2CO3H2CO3 CO2 (bubbles) + H2O.

We can find .................................................. in the shell of some crustaceous and eggs. If we submerge

an egg in an ................................ substance like vinegar, shell will dissolve in some days. Moreover,

because of the pores in the................................. the acid reacts with proteins and coagulate them, the

same as in a hard-boiled egg.

Activities1. Fill the gaps.

2. Search for the name of the acid which is contained in

vinegar:.....................................................

3. Complete this sentence and choose the correct option:

hydrochloric acid is (stronger/weaker) than.................................................

4. Make the drawing of the egg experience with the main things are needed.


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Experience twelve: ............................................................................................................................

.......................................................................................................................................................... .

Activities

1. Look at everything the teacher needs and write it in the two-line top gap.2. Complete the next situations with a drawing.

3. Translate everything below.

Experience thirteen: can, vessel, tongs, heater, water, ice cubes.

Put an empty can upside-down into a vessel with icy water. Take the can out and look at how much

water falls from it.

After that, fill a little spoon with water and throw it into the empty can. Heat the tin until white smoke

appears and take it with the tongs. Intriduce it in the icy water bath upside-down, and look what

happens.

Pocs instants desprs, el lquid

pujar pel got petit perqu laire que

cont es contrau en refredar-se, i la

pressi s menor que al principi. La

pressi atmosfrica lempeny.


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Activities1. Make a drawing of the situation.

2. Explain what happens, and why.

Experience fourteen: hair dryer, ping-pong ball.

Turn on the hair dryer pointing to the ceiling with the ping-pong ball on top. Look what happens

and write it: ................................................................................................................................

.....................................................................................................................................................


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When air moves fast, a low-pressure zone is created, so the air in the room keeps the ball in the

stream.

The ball flies up to the height where the air force is the same than balls weight.

..................................................................................................................................................................

................................................................................................................................................................

.........................................

Activities

1. Translate the explanation

2. Complete the drawing with low-pressure zone, stream force, weight, air-room pressure.

Experience fiveteen: scissors, paper

Cut the paper in two pieces. Take the two halfs as you see in the drawing and blow

through them.What do you

see? ........................................................................................................................... .

Give an explanation to this according to what you leraned in experience fourteen.

.........................................................................................................................................................

....................................................................................................................................................... .


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Now take a half of paper and blow as you see in the drawing, with the paper touching

on your below lip. What do you

see? ...........................................................................................................................

These effects (Bernoulli and Coanda) explain how an airplane is able to fly: Air has to move faster

in the top of the wing, so pressure is lower. The difference between the two pressures gives to the

wing an extra force to go up. (Translateit): ..........................................................................................................................................................................

..........................................................................................................................................................................

.......................................................................................................................................................................... .

Experience sixteen: Rugby ball, two balls with the same weight or size (more or less).

Throw the three balls (football/handball and rugby) to a bin 15m away. Fill the next grid with in, out,almost:

name Ball 1 Ball 2 Rugby ball1

2

3

4

5

6

7

89

10


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11

12

13

14

15

16

Throw the three balls as far as you can. Fill the nextgrid with a mark for the furthest ball

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16Ball1

Ball2

Rugby

Write here your conclusions about both (precision and length)experiences: ................................................................................................................................................

.........................

............................................................................................................................................................................

............................................................................................................................................................................

...........................................................................................................................................................................

...........................................................................................................................................................................

..........................................................................................................................................................................

..........................................................................................................................................................................

..........................................................................................................................................................................

Any object which moves into a fluid is able to create a turbulence, and it can brake the object. So an

aerodynamic shape is good to decrease this effect.

Finally, think about you have done and seen in the experience. Think about the explanation too. And

look these last pictures:


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Why do you think rugby ball is shaped in that way?............................................................................................................................................................................

...........................................................................................................................................................................

..........................................................................................................................................................................

............................................................................................................................................................................

...........................................................................................................................................................................

...........................................................................................................................................................................

..........................................................................................................................................................................

..........................................................................................................................................................................

..........................................................................................................................................................................

..........................................................................................................................................................................

...........................................................................................................................................................................

Experience seventeen: test tube, balloon, water, beer yeast, sugar.

Put a little of water (about a half) into a test tube. After that, add a spoon of sugar until the mixture

becomes a solution. Finally, add a spoon of beer yeast and close the test tube with the balloon.

Activities1. Make a drawing of the situation, writing all the names.

2. Translate the Spanish explanation:

Las levaduras utilizan el azcar como alimento y en el proceso liberan dixido de carbono, el cual

poco a poco va subiendo por la botella e inflando el globo. Este proceso de degradacin de los

azcares en ausencia de oxgeno y liberando dixido de carbono se llama fermentacin y es lo que

sucede cuando se prepara el pan; las levaduras utilizan los azcares de la mezcla del pan y producen el

dixido de carbono, es por eso que la masa del pan se infla.


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Exp. 18: To make a fertilizer gelatin for plants 100% organic, and a zero waste generation.

1st session

1. Into a 250 ml vessel, (glass or erlenmeyer) put the phase 1 water.

2. Weigh sorbic acid and potassium nitrate in a watch glass.

3. Dissolve sorbic acid and potassium nitrate, stirring.4. Weigh the CMC in the watch glass and pour it slowly into the 250 ml vessel, with continuous

stirring to avoid any lumps.5. Leave preparations in order of CMC gets well moisturized.

Activities. Translate the next words: Waste, weigh, stir, pour, lump, moisturize

2nd session

1. Weigh 1g of Al2(SO4)3 18H2O in a watch glass and dissolve it with 10 ml of water into a test

tube.


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2. Pour the solution containing aluminum slowly into the large vessel, stirring vigorously. The

mixture goes gradually thickened (*).3. Cut the gelatin, put it in molds, bags, plastic film, etc and take it home!

*At this point you will have the fertilizer gelatin 100% organic. This jelly is already sold nowadays

from a formula that contains water, sodium carboxymetilcellulose (sodium CMC), potassium nitrate,fumaric acid, NaAl(OH)2CO3 (DASC) in amounts that cant be said (trademark and patents). Theformula proposed to replace the commercial, without copying it and simplifying it, is as follows.

component component % By mass 200g

Sodium CMC 2,5 5 g

Potassium nitrate 1 2 g

Sorbic acid (preservative) 0,5 1 g

Water Phase 1 (90.5% approx) 181 ml 180 g

Al2(SO 4)3 18H2O 0,5 1 gWater Phase 2 (5%) 10 ml 10 g

How to use it: buried in the earth in a little hole.Afterwards the plant is watered, and this gives to theplant everything it needs for about 15-25 days so that we dont have to worry!

Activities . 1. Translate the next words: mixture, thicken, nowadays. 2. Translate the how to use ittext.

Experience nineteen: test tube, balloon, wooden stick, plastic straw, vinegar, bicarbonate, candle.

Put a little of vinegar into a test tube and a little of bicarbonate into the balloon. Afther that, connect

the test tube and the balloon. Look what happens and copy the reaction.

1. Make a drawing with everything its needed.


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Now, take the balloon out and leave the test tube absolutely empty. Make a little hole in the top of the

balloon with the stick, and pass the plastic straw through it.

Put a little of vinegar into the test tube again, and connect the balloon-straw system to the test tube.Look out! The straw musnt be into the vinegar, but hanging!

2. Make a drawing of the situation in this moment.

Finally, light a candle. Put a little of bicarbonate into the test tube and twist the straw mouth pointing

to the candle. Wite what

happens:.................................................................................................................................

This is how a fire extinguisher works: CO2 is heavyer than O2, so CO2 pushes O2 putting it apart of the

flame. If theres not oxygen, the fire extincts.

3. Translate the explanation.

Experience twenty: paper, pencil, pen, scissors, felt-tip pen, jar, alcohol, acetone.

- Cut the paper into four pieces.

- Put alcohol into the jar about the height of one cm.

- Make a line with pencil along the width of two papers in that way:


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- Make two marks over the pencil line: one with a black pen and other with a blue pen. Do the

same in the other paper with felt-tip pens instead of pens, but the same colours.

Look at the picture if you dont understand:

- Put the two papers into the jar (without touching each other) and close it.

Activities1. Write what happens:.............................................................................................................

2. What differences do you see between blue and black colour?

3. What differences do you see between pen and felt-tip pen?

Now, repeat the experience with acetone instead of alcohol and answer again questions 1, 2, 3. And

add this new question: What differences do you see between alcohol and acetone?

Experience 21: test tubes, sodium bisulfite, potassium permanganate solution, potassiumferrocyanide, tannic acid, ferrous sulphate, vinegar, yellow colouring, cupper nitrate, red cabbage

extract, hydrochloric acid, milk, soap, ear stick.

To make dark red colour

First couple: one of you has to fill a half of a test tube with potassium permanganate solution. The

other one adds a little of sodium bisulfite. Mix it until it changes the colour. And write a number

one in the tube.

Second couple: do the same as couple one.

To make blue colour

Third couple: One of you has to fill a half of a test tube with water and add a half of spoon of

potassium ferrocyanide. The other one has to fill a a half of a test tube with potassium

permanganate solution and add a little bit of ferrous sulphate and some drops of vinegar. Mix both

test tubes and write number two in the tube.

To make black colour

Fourth couple: One of you has to fill a half of a test tube with water and add a half of spoon of

tannic acid. The other one has to fill a a half of a test tube with potassium permanganate solutionand add a little bit of ferrous sulphate and some drops of vinegar. Mix both test tubes and write

number three in the tube.


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To make yellow colour

Fifth couple: You have to fill a test tube with water and solve a little bit of yellow colouring, andmix it. When its done, pour the half of this solution into another test tube and write number four in

both of them.

To make green colourSixth couple: You have to fill a half of a test tube with water and the other half of cupper nitrate,and mix it.

When its done, pour the half of this solution into another test tube and write number five in both of

them.

To make bright red colour

Seventh couple: One of you has to fill a test tube with hydrochloric acid and the other one adds a

little of red cabbage extract, and mix it. When its done, pour the half of this solution into another

test tube and write number six in both of them.

To make violet colour

eighth couple: You have to fill a quarter of a test tube with potassium permanganate solution, and

add water until the top. When its done, pour the half of this solution into another test tube and write

number seven in both of them.

1.Activity: Write in each test tube the different substances and say if its a physic process (solution) orchemist process (reaction).

Now, pour some milk into a dish and add some colouring drops over it. Look what happens. After that,

sink the ear stick into soap and touch the colouring drops.

2. Activity: Translate the explanation

Les molcules de sab tenen un extrem liposoluble i un altre extrem hidrosoluble. Aquesta

caracterstica fa que el costat liposoluble suneixi als greixos, mentre que el costat hidrosoluble fa que

el sab es dissolgui en laigua.

Per aquesta ra utilitzem el sab per rentar, ja que fa que les gotes daigua siguin ms petites i menys

cohesionades, i daquesta manera poden penetrar ms fcilment, per exemple, en les fibres dun teixit.

A ms a ms, el sab modifica la tensi superficial de laigua, debilitant-la. La tensi superficial s una

propietat de laigua que permet que certs objectes i ssers vius puguin surar a la superfcie de laigua

tot i tenir una major densitat.

El colorants no es dissolen rpidament perqu a la llet no noms hi ha aigua, si b ns un dels

components principals. Lexistncia de greixos fa que els colorants quedin concentrats.

Per qu sallunyen els colors rpidament quan toquem la llet amb el

sab? Perqu per una banda, estem trencant la tensi superficial de laigua. La tensi superficial suna propietat de laigua que fa que la capa de la superfcie es comporti com una pell ja que les

molcules de laigua satrauen entre elles i exerceixen una tensi.


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Some materials electrify each other when we rub them: there are electrons that go from one to the

other, so one material gets a negative charge and the other positive. When we electrify a fluorescent

light, the electrons of the gas into the tube get excited and colide with the fluorescent plate

producing light.

Translate the explanation!

Experience 23: 8 bananas, newspaper, plastic film

Buy 8 yellow bananas without black points.

- Put a pair of bananas somewhere in the kitchen.

- Put a pair of bananas into the fridge.- Put a pair of bananas into the fridge packed with newspaper.

- Put a pair of bananas into the fridge packed with plastic film.

Write here the date when you start the experience:................................................................... .

Act.1: after 2 days take out of the fridge the bananas and compare the four pairs:

Which pair has got more black points?.....................................................................................

................................................................................................................................................. .


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Do you see differences between the 6 bananas into the fridge?................................................

.................................................................................................................................................. .

Now you can eat the outsider bananas and leave the other 6 bananas into the fridge again to

continue the experience, packing them in the same way than the first day.

Act.2: 2 days later take out of the fridge the 6 bananas and compare them:

Do you see differences between the 6 bananas into the fridge?................................................

.................................................................................................................................................. .

Now you can eat the two darkest bananas.

Act.3: 2 days later take out of the fridge the 4 bananas and compare them.Explain if you thinkthere are differences between the preservation with film or

newspaper.....................................................................

......................................................................................................................................................................

...................................................................................................................................................................

Experience 24: balloon, wool, hair, tap.

Rub the balloon with the wool and approach it to a thin water current of a tap. What happens?

...................................................................................................................................................... .

Now, rub the balloon with your hair and approach it to the ceiling. Leave it alone. What happens?

.......................................................................................................................................................... .

When we rub the balloon with wool it electrifies: some electrons of the more external atoms of the

wool go to the balloon ones, so that the balloon gets negative charge and the wool positive. The

same happens when we do it with hair.

Translate the explanation:

El que passa amb lagua i la pintura del sostre sanomena inducci electrosttica: quan un objecte

electritzat (globus) sacosta a un de neutre, provoca una separaci de crregues en lobjecte neutre

per tal dacostar les de signe contrari (atracci electrosttica).


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Tradueix a langls:

Answer this question: Do you think that a wool rag is good to remove the dust of a television?Why?

...........................................................................................................................................................................

..........................................................................................................................................................................

......................................................................................................................................................................... .

Experience 25:Water, glycerin, oil, little glass, plate glass, droppers (3).

Put 2 cm of each liquid into the little glass. Wait until they stop flowing. Write them in order of decreasing

density:........................................................................................................................................................... .

Make a drawing of the three liquids in the glass.

Now, try to fill three droppers with each liquid. After that, one of the members of the group has to hold the

plate glass and the other three leave a drop of each liquid fall over the plate. Look the three drops climb

down. Write them in the order they arrive to the end of the plate glass:

1st: 2nd: 3rd:

Activities


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1. The first observation depends on density, while the second one depends on viscosity. What differences

do you see?

2. Say if its true orfalse:

- Water density is higher than oil density.

- Water viscosity is higher than oil viscosity.

- Glycerin is the most dense and viscous of the three liquids.

3. Translate the explanation:

Podem definir la viscositat dun lquid com la resistncia a fluir, i depn de les forces de cohesi entre

les molcules. Normalment, els lquids ms viscosos sadhereixen ms a les superfcies, per

ladherncia depn tamb de la tensi superficial del material. Per exemple, la tensi superficial dels

plstics s menor que la del vidre i la dels metalls.

Experience 26: electric cable (50 cm), iron nail (10-12 cm), 9V battery, paperclips.

Enrotlleu el cable al voltant del clau fent tantes voltes com pugueu. Connecteu els dos extrems del cable als

borns de la pila i acosteu la punta del clau als clips. Qu passa? (In English)...................................................

......................................................................................................................................................................... .

I means electric intensity and the arrows show the direction of the magnetic field created.

An electric field always creates a magnetic

field, and the opposite happens too.

We do not usually feel this, but when we roll

a cable we create a solenoid: the magnetic

field increases so much that we can create a

magnet with iron.


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This is how a electromagnet works: it has got a big solenoid inside, so when we connect the electricity the

magnetic field attracts iron objects, but when we turn off electricity the magnetic field disappears and the

object falls.

Activity: Translate both explanations about the solenoid and electromagnet.

Experience 27: napkin, bed protector, water, scales.

Weigh the napkin or the bed protector and write here its weight:................................................. .

Measure the long and width of the napkin or bed protector, and calculate the area:

Long:

Width:

area:

Pour water onto the napkin or the bed protector until its not able to absorb it. After that, weigh it again and

write here its weight:....................................... .

Activities1. Calculate how many times can absorb its weight in water.


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Weight wet/weight dry =

2. Which of two (bed protector or napkin) asborbs more water? To compare it, make this:

Napkin: mass of water/area =

Bed protector: mass of water/area =

Napkins have an amazing absortion capability: Theyve got sodium polyacrilate inside, a kind of plastic which

is able to change the sodium ions by water molecules. (Translate it):

When you finish, open the napkin with a cutter and look the polyacrilate gel formed.

Do you think its possible to recover a napkin? You can try it hanging it as the clothes, or leaving it next to a

heater.

Experience 28: microwave, bulb, CD, vessel.

Place the CD in the vessel, and both things into the microwave. Turn on the microwave and wait some

seconds. What happens? (turn off immediately!!!!!)................................................................................

................................................................................................................................................................. .

After that, repeat it changing the CD by the bulb. What happens? ..........................................................

................................................................................................................................................................... .

When we do it with the CD, we have to know that the CD is made mainly of plastic, but it has a little of

aluminum too. The CD reflects the microwaves, but it absorbs a little part that heats it. (Translate it)


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When we do it with the bulb, we have to know that its full of a gas. The energy of microwaves turns the

gas into plasma: the electrons of the gas atoms get excited and separate from its orbits, and every time that

they come back produce light.

(Translate it

):

Its known that the tungsten filament of the bulb is able to bear temperatures about 3000 C. So if it got

carbonized this would mean that temperature inside the bulb rises over 3000C!!! (Translate it)

Experience 29: drill, black/white fotocopy.

Cut a big copy of a drawing like this:

Bore it through the drill and turn it on. What happens?.......................................................................

.............................................................................................................................................................. .

Into an eye there are 3 milion of cone cells in the fovea of the retin. There are three kind of them, and they

activate due to the different light frequences: one of them with the yellow-green light, the second kind with

green-blue light and the third kind with blue-purple light.


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All the colours we see are made by combination of the different cells activated. With white colour, they

activate all together; with black they dont activate. In this experience, we are giving to the eye a

combination of black and white shapes so fast that the different cons activate, stop and reactivate constantly,

produing a mixture of colours.

Translate the explanation:

Name:

Write here the five experiences did you like the most:

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-

-

-

-Explain three things that you have leraned:

Experiments That's Science

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