Diagram 6 shows copper refining using electrolysis

DIAGRAM 3

[3 marks](a) On diagram 3, name P, Q and R by using the following information

(b) State the energy changes in this electrolysis process

(c) Why metal P becomes thinner in the electrolysis process?

(d) State one use of electrolysis other than metal refining.

ANSWER:(a) P : Impure Copper

Q : Pure CopperR : Copper (II) sulphate solution 3

b) Chemical energy to electical energy(c) P metal dissolve to form positive ion(d) Metal extraction//Metal electroplating

Pure copperImpure copperCopper(II) sulphate

Q:.........................................................P :.........................................

R :.........................................................

Diagram 4 shows radioactive radiation in electrical field.

(a) Name radioactive rays T and V in Diagram 4(b) (i) Which ray is positively charged?

(ii) Explain your answer in b(i)

(c) Which ray is used to sterile food before packaging?

(a) State the method that can be used to stop ray U from emit to the environment?

ANSWER:

a) T : Beta ray V : Alpha ray(b) (i) V ray/Alpha ray (ii) because it deflect to negative plate(c) U ray/gama ray(d) Placed in lead block//concrete container

- - - - - - -

+ + + + +

T : -------------------------

V : -------------------------

U

Radioactive source

Diagram 6 shows the arrangement of atoms in a steel.

(a) Name the atom ( i ) P : ( ii ) Q :

(b) What is the role of atom P in the steel above?

(c) State two new characteristics of the steel compared to the iron.

(d) Name one alloy other than steel.

ANSWER:(a) (i) P : Carbon

ii) Q : Iron(b) Foreign atoms/P/carbon prevents the atoms of pure metal from sliding over one another(c) Harder// stronger//resistant to corrosion (any two)(d) Brass//Pewter//Bronze

Diagram 5 shows a cross section of human brain.

DIAGRAM 5

atom P

atom Q

A

B

(a) Based on Diagram 5, name the structures labelled A and B.

(b) State one function of structure A .

(b) State two effects of drug abuse on the brain

ANSWER:

(a) A : CerebrumB : Cerebellum 1 m

(b) Control the voluntary action//control speech/hearing/vision(c) Brain damage/depression/hallucination/stay awake or

active/decrease stress/Slow down the reaction time/lost sense of smell/vision/becomes intellectuallyincapable(any two suitable answers)

(d) Cannot maintain posture and body balance

Diagram 2 shows an experiment to study the reactivity of metals when react with oxygen.

Three types of metals X, Y and Z are used and the results are shown in the Table 2.

Metal Observation

XBurns with bright light

YGlows dimly

ZBurns moderately

TABLE 2

(a) Write down one inference that can be made from observation in Table 2

(b) State the following variables in this experiment.

Heat Heat

Glass wool

(

Metal filling

(Serbuk logam)Potassium manganate (VII)

DIAGRAM 1

(i) Manipulated :…………………………………….

(ii) Constant :…………………………………………

(c) Based on the results in Table 2, arrange the reactivity of the metals from the most reactive to the least reactive.

(d) If the metals used in this experiment are magnesium, zinc and iron, predict what is metal X?

ANSWER:

(a) Metal X is the most reactive // Metal Y is the least reactive(b) (i) Type of metal

(ii) Amount/Quantity/Mass of metal(c) X, Z, Y(d) Magnesium

Diagram 3 shows the formation of twins.

(a) Name process P.(b) Name the cell division at stage Q.(c) Describe how the two embryos are formed.

Diagram 2

(d) State one characteristic of the foetuses formed.ANSWER:

(a) Fertilisation (b) Mitosis(c) The zygote formed divides into two cells , then separate and move

apart. Each zygote continues to divide through mitosis, forming two

embryos. 1(a) The foetus have the same genetic content// gender

Essay

1. There are two types of variation, continuous variation and discontinuous variation.

(a) Give four differences between continuous variation and discontinuous variation. [4 marks]

(b) Diagram 8 shows various characteristics of human being.

Study the above characteristics. Explain how you would develop a concept based on the information in Diagram 8

Your explanation of the concept should include the following:

Identify two common characteristics [2 marks] Develop initial concept [ 1 mark] Give another example and a non-example in relation to the concept

[2 marks] State the actual concept [ 1 mark]

ANSWER: (a)

Continuous variation Discontinuous variation

Variation

(Variasi)

Ability to roll tongue Blood group

Type of earlob Presence of dimples

DIAGRAM 8

Does not show obvious differences in characteristics

Shows obvious differences in characteristics

Influenced by environmental factors

Influenced by genetic factors

Not inherited Inherited Form a normal distribution graph Does not form a normal

distribution graph 4 m (b)

Two common characteristics: Shows obvious differences in characteristics Influenced by genetic factors

Initial concept:Variation that shows obvious differences in characteristics and influenced by genetic factors is discontinuous variation.Another example : Fingerprint // type of hair Non-example : Height // weight Actual concept:A discontinuous variation is a variation that shows obvious differences in characteristics and is influenced by genetic factors.

2 (a) (i) Draw and label the arrangement of particles in copper and bronze

(ii) Explain why bronze is harder than copper?

(b) Diagram 9 shows examples of alloys

DIAGRAM 9

Study the above examples. Explain how you would develop a concept of alloy. Your explanation of concept should include the following:

Alloys

(Aloi)

Pewter

(Piuter)

Bronze

(Gangsa)

Brass

(Loyang)

Identify two common characteristics Develop initial concept. Give other examples and non-examples in relation to the

concept. Explain the actual concept

ANSWER: (a) (i) Able to draw and label the arrangement of particles in copper and bronze.

(ii) Layers of copper atoms can slide over one another when sheared.Tin atoms in bronze prevent copper atoms from sliding easily

over 1 mone another.

(b) (i) Two common characteristics: Mixture of two or more metals//mixture of a metal with a

small amount of non-metal

Harder // more rust resistance(ii) Initial concept:

Substance made up of two or more metals (in different percentage) and

have better physical characteristics than its pure metal is an alloy

(iii) Another example : ( steel / duralumin)Non – example : Aluminium / carbon

(accept any suitable answers)(iv) Actual concept:

Alloy is a substance made up of two or more metals (in different percentage)

and have better physical characteristics than its pure metal.

3 Study the following statement.

copper

Copper atomCopper atom

Tin atom

bronze

The height of students in a classroom varies from one student to another student and there are many values between the shortest student and the tallest student.

(a) Suggest a hypothesis to study the above statement.

(b) Describe an experiment to test your hypothesis in 10(a) according to the following criteria.

I. Aim of the experiment II. Procedure or method

III. Tabulation of data and sketch the graphIV. Conclusion

ANSWER:a) The height of a student shows a continuous variation.b) i) to show that the type of the variation for the height of the students in a

class is a continuous variation.ii) - the height of each student is measured and recorded.

- The height of the student is classified into appropriate categories in the table.

- The number of students for each category is recorded in the table.- A histogram is drawn based on the data recorded in the table

c)Tabulation of dataHeight(cm)No.Of students

d)The height of a student in a class shows a continuous variation.

4. (a) State two sources of water pollution and two effects on the environment

(b) The Environmental Department had received a complaint from Kampung Indah’s residents regarding to variety species of fishes found floating dead in the river. The result of the investigation made on the sample taken from the river proves that the river was contaminated with effluents from the nearby palm oil factory.

Explain three methods that could be done by the factory management in order to eliminate the sewages produced. Your explanation should base on the following aspect:

I. Identify the problem. II. Explain three alternatives to conserve the river.

III. List two alternatives according to their priority.

ANSWER:

a) Disposal of rubbish / sewage / fertilizer / toxic substance/chemical substance

Effects: Kill aquatic organisms / destruction of habits / change the pH value of the water / leads to lack of oxygen

b) i) the variety species of fishes found floating dead in the riverii) heating liquid effluents from the factory before dispsing them into the river

- Recycle effluents frm the factory into useful substances / animals feed / compost fertilizer

- Burn the oil palm waste can lead to release of thick smoke.

iii)- treating liquid effluent- Recycle solid effluent- Burn the waste

5. Study the following statement:

You are given boiling tube, cork stopper, delivery tube glass trough, water, magnesium powder, zinc powder and dilute sulphuric acid.

(a) Suggest a hypothesis to investigate the above statement

(b) Describe an experiment to test your hypothesis in 10(a) based on the following criteria

(i) Aim of the experiment

(ii) Identification of variables

Reaction of different metals with acid will produce different volume of gas.

(iii) List of apparatus and materials

(iv) Procedure and methods

(v) Tabulation of Data

ANSWER:

(a) Reaction of reactive metals with acid produce a higher volume of gas/the more reactive the metal the higher the volume of gas produced

(b) (i) To study the reactivity of metals with acid

(ii) Manipulated variable: type of metal Responding variable: volume of gas collected Controlled variable: concentration of dilute sulphuric acid

(iii) boiling tube, cork stopper, delivery tube, glass trough, water, magnesium powder, zinc powder, copper powder dilute

sulphuric acid and test tube.

5. The volume of gas collected is recorded in a table.

(v) Tabulation of data

Type of metal Volume of gas (cm3)MagnesiumZincCopper

(iv) 1. 5 cm3 of dilute sulphuric acid is poured into a boiling tube.

2. A spatula of magnesium powder is added into the boiling tube. 3. The gas released is collected in a test tube. 4. Steps 1-3 is repeated using zinc and copper powder.