In 1869, Russia's Dmitri Mendeleev and Germany's Lothar Meyer... Meyer Mendeleev.
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Transcript of Take Out Pencil Annotated article. Catalyst 1.What was Johann Döbereiner’s contribution to...
Take Out
PencilAnnotated article
Catalyst1. What was Johann Döbereiner’s
contribution to chemistry in 1829?
2. Why is Dmitri Mendeleev considered the “Father of the Periodic Table”?
3. Why do you think the placement of H and He are considered “unresolved issues”?
Your task in class today, and to finish for class on Tuesday (2nd & 3rd periods) or Wednesday (4th & 5th periods) is to create a timeline of the history of the periodic table. You may use your reading packet, as well as any other information you find in books and online. The rubric must be attached to the front of your timeline before it will be accepted.
• Your Period Table Timeline must:
• Include at least 6 dates/time periods• Include a written description of the event next to the date/time
period• Include a visual representation next to each date/time period• Take up almost all space on an 8.5 x 11 sheet of printer paper
(you may use a larger piece of paper too)• Include a title• Include your full heading on the back
HomeworkComplete your Periodic Table Timeline and bring in to class, with rubric attached to the
front
If you have colored pencils, please bring them with you to class tomorrow
Take Out
Catalyst sheetPencilScience Notebook
Make a pile of timelines in center of table w/ rubric attached
Tape paper I give you onto page 48
CatalystComplete page 48 in science notebook with your group
On your Catalyst sheet, describe in detail the patterns that you see on page 48
Why isn’t the world made only of elements? How do the atoms of different elements combine to form molecules?
The answers to these questions are related to electrons and their energy levels. And the roadmap to
understanding how electrons determine the properties of elements is the periodic table.
Valence Electrons: The key to bondingYou have learned that electrons are contained
within energy levels. An atom’s valence electrons are those electrons
that are in the highest energy level and are held most loosely.
The number of valence electrons in an atom of an element determines many properties of
that element, including the ways in which the atom can bond with other atoms.
8 is the lucky number!!Most atoms are more stable – less likely to
react – when they have filled their outer most energy level OR if they have eight
valence electrons (their outer s & p orbitals are full).
In your notes, draw the electron dot diagrams of hydrogen, carbon, and oxygen.
How many more electrons are needed to make an oxygen atom stable? A hydrogen atom? A
carbon atom?
A row of elements across the periodic table is called a period. Hydrogen and helium make up the first period. Label the periods.
Elements in the same column are called a group or family. Label the groups of your periodic table.
Neon
How many valence electrons?
Argon
How many valence electrons?
Krypton
How many valence electrons?
Xenon
How many valence electrons?
A period ends when the highest energy level has eight electrons.
The elements within a group always have the same number of valence electrons, and for this reason, the elements within a
group have similar properties.
Why the name “noble gas”?Most atoms are more stable – less likely to
react – when they have eight valence electrons.
The other elements strive to be like this! They strive to be stable.
On your periodic table, color your noble gases orange.
When atoms react they usually do so in a way that makes each atom that is participating in
the bond more stable.
One of two things may happen:1.The number of valence electrons increases to
eight (or two in the case of hydrogen).2.The atom gives up its most loosely held
valence electron(s).
Homework
Complete page 52 in science notebook
Homework
Update Vocabulary using website
Study Vocabulary and Periodic Table notes for quiz on Friday
Take Out
Catalyst SheetPencilScience notebook open to homework
Catalyst1. Write down everything you
know about the Noble Gases. 2. Why is helium in group VIIIA
and considered a Noble Gas, even though it doesn’t have 8 valence electrons?
One of two things may happen:1. The number of valence electrons increases to eight (or two
in the case of hydrogen).2. The atom gives up its most loosely held valence electron(s).
What does oxygen need to become stable?
Atoms that react this way become chemically combined, or bonded
together. A chemical bond
is the force of attraction that
holds two atoms together as a result of the
rearrangement of valence electrons between them.
Look at the elements in the column just to the left of the noble gases. The elements in group VIIA are called the halogens. Atoms
in the halogen family have seven valence electrons. A gain of just one more electron gives these atoms the stable number of 8 electrons. As a result, elements in the halogen family react easily with other elements whose atoms can give up or share
electrons.
When iodine, a halogen, reacts with aluminum, a purple gas is produced
Bromine, a halogen, reacts vigorously with
hydrogen
http://www.youtube.com/watch?v=gFGwY_S4j_M
http://www.youtube.com/watch?v=R6bBs2D0cpA
At the far left side of the periodic table is Group IA,
called the alkali metal family. Atoms of the alkali metals
have only one valence electron. Therefore, alkali
atoms can become chemically more stable by
losing their one valence electron. This makes them
very reactive.Color the alkali metals yellow.
http://www.youtube.com/watch?v=fmOd8_ReNnQ
The alkaline earth metals are in Group IIA
The alkaline earth metals are silver
colored, soft metals, which react readily
with halogens to form ionic salts, and
with water, though not as rapidly as the alkali
metals, to form strong alkaline (basic) hy
droxides.Color the alkaline earth
metals red
http://www.youtube.com/watch?v=DFQPnHkQlZM
Reaction of magnesium with carbon dioxide
Dry Ice = the solid form of carbon dioxide
http://www.youtube.com/watch?v=wqErrNvns4o
Metals vs Non-MetalsMetals – Give up their valence electrons during
chemical bondingNon-Metals – Gain valence electrons during
chemical bonding
Color the transition metals purple
Take Out
CatalystPencilScience notebook open to Vocabulary
CatalystDescribe everything you know
about alkali metals and alkaline earth metals
CatalystDescribe the difference between a
metal and non-metal
Other metals polonium Very rare radioactive metal that is used as fuel in nuclear reactors; it emits
radiation that is much more powerful than that of uranium.bismuth Relatively rare metal that is used especially in alloys and cosmetics and in
medicine (treatments for gastric ulcers and diarrhea).lead Heavy toxic metal that is used to prevent corrosion, as a protection against
radiation and in accumulator batteries, paint and glass.thallium Metal that is used especially in infrared detectors and some kinds of glass.tin Metal that is used especially as an anticorrosive for copper and steel and
as a component in the preparation of bronze, welding and toothpaste.
indium Very rare metal that is used especially in race car engines and electronic
devices, and as a coating for glass.gallium Rare metal that is used especially in high-temperature thermometers,
electroluminescent diodes and television screens (the color green).aluminum Light metal that is used especially in aeronautics, cars, buildings, electric
cables, kitchen utensils and packaging.
Color the “Other Metals” brown
What happens when an atom loses or gains electrons?
An ion is formed
An ion is a charged atom or particle
Cation = a positively charged particle (electrons were lost)
Anion = a negatively charged particle (electrons were gained)
Ionic bond involves TRANSFER of electrons
Ionic Compounds
Several elements, known as metalloids lie along a zigzag line between the metals and the nonmetals. Depending on the
conditions, these elements can react as either metals or nonmetals. The metals have from 3 to 6 valence electrons and can either lose or share electrons when they combine
with other elements.Color these metalloids blue
The elements below are nonmetals, and have four or more valence electrons. Like the halogens, these nonmetals
become stable when they gain or share enough electrons to have a set of eight valence electrons.
Color these nonmetals green
Covalent bonds involve SHARING of electrons
Covalent Compounds
HydrogenHydrogen is considered to be a nonmetal. It is located above
Group 1 in the periodic table because it has only one valence electron. However, even though hydrogen is a reactive
element, its properties differ greatly from those of the alkali metals.
http://www.youtube.com/watch?v=fesgl5Cs5FY
Freefall
http://www.youtube.com/watch?v=dOoHArAzdug
Homework
Update Vocabulary
Study all Vocab and Periodic Table Notes for Quiz on Monday