GOZO COLLEGE Secondary School KULLEĠĠ TA’ GĦAWDEX Skola Sekondarja

Half Yearly Exam 2016

Year 8 Levels: 5 - 8 SCIENCE Time: 1:30min

Name: _________________________ Class: Year 8 _____________

Instructions to Candidates Answer all twenty questions. Write only on this paper. Do not spend too much time on any one question only. Good English and orderly presentation are important.

Information to Candidates

The mark of each question is written beside or at the end of each question. Each correct answer carries one mark. The total mark scored will be given as a percentage mark.

Question 1 2 3 4 5 6 7 8 9 10 11 12 13

Maximum 10 3 4 5 7 12 14 4 8 5 11 13 7

Mark

Question 14 15 16 17 18 19 20 Paper total Final mark

100%

Maximum 10 10 5 4 5 5 8 150

Mark

X 0.67 =

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Q1. Look at the pictures. Then answer the questions on nutrients. (10 marks)

fish pork chop butter walnut olive oil corn

(Use examples from the pictures above)

a) Name two foods rich in proteins. i. ………… and ii. ………………………….

b) Why are proteins important in our diet? ………………. and …………………..

c) Sugar and starch are rich in which nutrient? …………………………………….

d) Name two foods rich in fat. i. …………………… ii. ……………………………

e) Why are fats important in our diet? ………………………………………………..

f) What are the hazards of too much fat in our diet? ………………………………

g) What do you understand by a balanced diet? ……………………………………

…………………………………………………………………………………………

Q2. People do not always eat a balanced diet. (3 marks) Draw one line from each fact about a person’s diet to the organ it harms. Draw three lines

Fact about the diet Organ harmed

heart

Not enough calcium

intestine

Not enough fibre

lung

Too much fat

bones

Q3. The table shows the mass of water, fat, fibre and vitamin C in 100 g of potato

cooked in three different ways. (4 marks)

a

.

a. Use the table to fill the blanks.

i. Chips are crisper than boiled potatoes because chips contain less ………

ii. Most of the fibre in a baked potato is in the ………………..………………..

Water in

g Fat in

g Fibre in

g Vitamin C

in mg

100g of chips 57 7 2 9 100 g of boiled potatoes 80 Hardly any 1 6 100g of potatoes baked in its skin 63 Hardly any 3 14

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b. Use the information in the table to work out how much vitamin C there is in:

i. 200g of chips …………………………………………….. ……….. mg

ii. 200g of potatoes baked in its skin …………………….. ……….. mg

Q4. People in different countries eat different amounts of starch. A scientist compared the amount of starch that people ate to the number of people with cancer of the large intestine. (5 marks)

The scatter graph below shows her results. Look at the scatter graph.

(a) (i) Which country had the greatest proportion of people with cancer of the

large intestine? ………………………………………………………..

(ii) What conclusion could you come to about the effect of eating starch on

getting cancer of the large intestine? ………………………………………

(b) (i) Starch is a carbohydrate. Which two of the following foods are good sources

of starch? Tick the two correct boxes.

bread cheese fish

chicken tomatoes pasta

(ii) What other type of nutrient, needed as part of a balanced diet, keeps the intestine working well and prevents constipation? Tick the correct box.

fat fibre minerals protein vitamins

0 5 10 15 20 30

Number of people, per 100 000, with cancer of the large intestine

Finland

Britain Netherlands

United States

50

100

150

200

250

300

350

400

China

Am

ount o

f sta

rch

eate

n

(g/d

ay)

Ireland

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Q5. Fill in the blanks with the given key words. (7 marks)

bones ― cereals ― constipation ― iron― scurvy ―teeth ― vegetables

a. ___________ is a mineral important in making red blood cells.

b. Calcium is important for healthy ___________ and ____________.

c. Two foods rich in fibre are ______________ and ___________.

d. Fibre is important in our diet as it prevents ____________.

e. Vitamin C prevents a condition known as _____________.

Q6. a. Use the given key words to label the digestive system. (6 marks)

anus - gullet - large intestine - mouth - small intestine - stomach

b. Digestion can be mechanical (physical) or chemical.

Mark the type of digestion represented by each function. (6 marks)

Organ Function Type of Digestion

Mechanical Chemical

mouth teeth grind food

saliva changes starch to sugar

stomach acids allow enzymes to break down food

food mixed and squeezed

Small intestine Enzymes from pancreas complete digestion

Bile from liver breaks fat into small drops

B

C

A

E

F

D

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Q7. a. Micro-organism can cause infections in the body. (10 marks) Draw straight lines to match each disease to the micro-organism which causes it and to the way the disease is spread.

The first one has been done for you.

Microbe Disease How disease is spread

Bacteria Common flu Eating infected food

Virus Food poisoning Coughing and sneezing

Virus Athlete’s foot Close contact

Fungus Chicken pox Public showers

Bacteria Tuberculosis Blood contact

Virus AIDS Coughing and sneezing

b. The body can defend itself against disease in a variety of ways. Draw straight

arrows to match up each method of defence to the correct description from those listed below: (4 marks)

Body defences Description

Clotting of blood chemical that kills most microbes

Skin made up of white blood cells that kills microbes

Immune system stops most microbes from entering the body

Stomach acid seals wounds quickly to prevent entry of microbe

Q8. This question is about micro-organisms. Tick the correct box. (4 marks)

i. Which is the smallest type of microbe? bacteria fungus virus

ii. Which type of microbes are seen in the diagram?

bacteria fungus virus

iii. Which type of microbes are usually made up of branched threads?

bacteria fungus virus

iv. Which of the following micro-organisms help the bread to rise in baking?

yoghurt starch yeast salt

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Q9. a) Micro-organisms can be useful to us. Name two useful types of microbes and write what they are these used for? (2marks)

Name of useful microbe Where it is used

b) Are antibiotics effective against influenza? Explain why. (2marks)

………… ………………………………………………………………………………..

c) How can you lessen the risk of getting salmonella when you cook food which

was frozen? ………………………………………………………………… (1 mark)

d) Name two situations where you need to wash your hands: (2 marks)

i. .…………………………………… ii. ……………………………………………….

e) Scurvy is a disease that sailors often got on long voyages. It was discovered that scurvy could be prevented by eating oranges and lemons. This suggests that scurvy is a disease caused by: tick the correct box. (1 mark)

a microorganism lack of exercise

exposure to sea air a nutritional deficiency

Q10. The diagram shows part of the breathing system.

Use the given key words to name the parts labelled A, B, C and D. (5 marks)

alveolus diaphragm lung rib trachea

Q11. a. Crossmatch organ found in a human body system with function. (4 marks)

Organ Function nose gas exchange lungs muscle that controls breathing diaphragm moistens and filters air

E

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b. Which human body system performs these functions? Tick the correct box.

skeletal circulatory digestive respiratory

c. The diagram below shows one alveolus and its blood supply. (3 marks)

(i) Gas A enters the blood from the alveolus. Gas B leaves the blood and enters the alveolus. What are the names of gases A and B?

Gas A is ………………………

Gas B is ………………………

(ii) Give one reason why it is easy for gases to pass across the wall of an alveolus. ……………………. ………………………...…………..…….……..….…………

d. The diagram below shows a nicotine molecule. It contains atoms of three elements. Nicotine in tobacco smoke enters the blood through the alveolus.

(4 marks)

(i) Nicotine is a compound. How does the diagram show this?

……………………………………………….……………………………………………

(ii) When nicotine in a cigarette is burned in air, nitric oxide is formed from the

nitrogen in the nicotine. Look at the elements in nicotine.

Give the names of two other compounds formed when nicotine burns in air.

a. ……………………………………….. and b. ……………………………………..

(iii) Name one reason why smoking is a dangerous habit to health.

…………………………………………………………………………………………

Q12. Fill in the gaps with the given key words. (13 marks)

atom carbon dioxide compound equation formula metals

mixture molecule nitrogen non-metals Periodic simpler symbol

Substances that cannot be broken down into anything ____________ are called

elements. These are made up of only one type of __________. Each element is

represented by a chemical _____________. All the elements are shown in

Gas B

tiny blood vessel

Gas A

Alveolus (air sac)

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the _____________ table. The elements on the left side of this table are known

as _____________ whilst those on the right are _____________.

When two or more elements chemically join together, a new type of substance is

formed. Such a substance is called a ______________ and is represented by a

_____________. The smallest particle of a compound is called a

_______________.

A chemical reaction can be shown by a word ___________________.

A ____________ is made up of different substances NOT chemically combined

together. For example, in air there are three gases mixed together: oxygen and

_____________ are elements whilst _______________ is a compound.

Q13. The diagram shows part of the Periodic Table. (7 marks) Use the symbols on the diagram to answer the following questions.

a) Give the symbols for two metals. ........................ and ...............................

b) Give the symbols for two non-metals. ...................... and .............................

c) Give the symbol for an element that is a gas. ………………………........................

d) Give the symbols for two elements that react to make lithium chloride.

.................................... and ....................................

Q14. a. The oldest coin in the world is nearly 3000 years old. Very old coins are

often made from pure gold. What type of substance is pure gold? Tick the correct box. (1 mark)

An element Compound Solvent A mixture

This is a list of the properties of gold.

A Shiny appearance B Very unreactive C Good electrical conductivity

D Yellow colour

Au Gold

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b. Use the letters A, B, C and D to answer the following questions. (3 marks)

i) Which property explains why gold coins are not affected by oxygen in the air? …...

ii) Which two properties are true for all metals? …….… and …….…

iii) Draw lines to match each metal to its symbol. (3 marks) Use the information in the table to help you.

Element Symbol

sodium Pb

iron Na

lead Fe

iv) Silver has the symbol Ag. Suggest why the symbol for silver is not Si.

........................................................................................................... (1 mark)

v) Circle the names of two other metals. (2 marks)

sulphur zinc aluminium carbon nitrogen

Q15. Three balloons are filled with three different gases. (10 marks)

a) The diagrams show the particles of gas in each balloon.

How do the arrangements of particles in the balloons show that they are gases?

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

b) Tick the balloon which does not contain any molecules?

argon oxygen carbon dioxide

c) Tick the balloon which contains molecules of an element?

argon oxygen carbon dioxide

d) Tick the balloon which contains molecules of a compound?

argon oxygen carbon dioxide

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liquid

Particle layer of insoluble titanium dioxide

e) i) Carbon dioxide is sometimes sold as ‘dry ice’. Dry ice is solid carbon

dioxide. How is the arrangement of particles in dry ice different to the

arrangement of particles in carbon dioxide gas? ………………………………..

…………………………………………………………………………………………

ii) The formula for carbon dioxide is CO2. What do the letters C and O stand for

C = ................................ O = ………………………….

f) Mark the statements about the gases in the balloons true or false?

Statement True False

Argon is a non-metal

Carbon dioxide molecules have more carbon atoms than oxygen molecules

All of the balloons contain compounds

Q16. Fill in the blanks by using some of the words listed below: (5 marks)

solvent dissolving solution insoluble solute

Some people cannot drink tea or coffee without adding sugar to it. The sugar

disappears in the warm water. This process is known as ………………………...

The water, which is the substance that makes the dissolving is called a ……….

Sugar is called the ………………... Since sugar dissolves in water it is

………………………...

Not all solids can dissolve in water. Sand cannot dissolve in water and so it is

……………………………………..

Q17. (a) Samantha opened a tin of white paint. The paint consisted of a liquid and

particles of titanium dioxide that are insoluble in the liquid. The paint had separated into two layers, as shown below. (4 marks)

Tick the correct box.

(i) What type of substance is the paint?

a compound an element a mixture

(ii) What type of substance is titanium dioxide?

a compound an element a mixture

(iii) Why did the particles of insoluble titanium dioxide sink to the bottom?

……………………………………………………………………………………..

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(b) Samantha stirred the paint and used it to paint a window frame. She got some of the paint on the glass.

Samantha could not get the paint off the glass with water.

When she used a different liquid called white

spirit the paint came off.

Why could she remove the paint with white

spirit but not with water?

…………………………………………………

………………………………………………………………………………………………..

Q18. Use the words listed below to choose the easiest way of separating the

following mixtures: (5 marks)

filtration magnet distillation chromatography by hand boiling

Mixture Separating method

i If you wanted to separate iron filings from sand

ii Permanent marker ink is best separated by using

iii If I want to separate mud from water

iv To get salt from seawater

v To separate peas from dried beans

Q19. a . Rock salt is a mixture. Pure salt can be separated from rock salt. Sentences A, B, C, D and E describe how pure salt can be obtained from rock

salt. The sentences are not in the correct order.

A Evaporate the water by heating

B Mix the rock salt with water

C Crush the rock salt

D Stir to dissolve the salt

E Filter the mixture

Put the sentences A, B, C, D and E in the correct order.

The first one has been done for you.

b. Does rock salt evaporate when its solution is heated? …………………… (5 marks)

C

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Q20. The diagram below shows the students’ arrangement of the glassware for carrying out an experiment. (8 marks)

a) What is the name of this separation technique? ……………………………………

b) Which processes occur during this separation method? Tick the correct box.

condensation then evaporation melting then boiling

melting then evaporation evaporation then condensation

c) Name the pieces of apparatus in the diagram labelled X and Y

X is ………………………………... Y is ……………………….…………

d) Where in the diagram would you put the solution you want to separate? ………..

e) What is the purpose of the water that is flowing into and out of the piece of

apparatus labelled Y? ………………………………………………………………...

f) Give the name of the colourless liquid that collects in the test-tube? ……………

g) Name the additional piece of laboratory equipment that is needed to carry out

this experiment. ……………………………………………………………………..

THE END

Thermometer

Water out Y Glass tube

X

Water in Test tube heat