Chemistry
Class 8 Science Test
Time: 1:30 hrs
Full marks: 40
Choose the correct option:
1. The most reactive metal is:
(a) Iron (b) Gold (c) Zinc (d) Potassium.
2. The liquid metal at room temperature is :-
(a) Mercury (b) Bromine (c) Sodium (d) Gold.
3. Non-metals are:
(a) generally liquids (b) generally gases (c) generally solids and gases (d) generally gases and liquids
4. The metal which is stored in kerosene:
(a) Phosphorus (b) Magnesium (c) Sodium (d) Magnesium
5 The non-metal which is liquid at room temperature is:
a) Carbon (b) Iodine (c) Bromine (d) Chlorine.
6. Materials around us can be classified into
(a) Elements and compounds (b) Metals and non-metals c) Acids and bases (d) None of these.
7 .All metals are solids except
(a) Sodium (b) Calcium (c) Mercury (d) Hydrogen.
8.Metal oxides are of nature
(a) Acidic (b) Basic (c) Neutral (d) All of these.
9 The metal which can be cut with a knife
(a) Sodium and potassium (b) Barium and calcium (c) Sodium and mercury (d) Potassium and calcium
10 When non-metals react with water then
(a) Hydrogen gas is formed
(b) Carbon dioxide gas is formed
(c) Non-metals do not react with water
(d) None of these.
Answer in complete sentences:
1.Explain displacement reaction with the help of an activity.
2.Explain the reaction of non-metals with oxygen.
3. Write five uses of metals and non-metals.
4. Write the difference between metals and non-metals on the basis of their 4 chemical properties.
5. Name two most ductile metals and the hardest known non-metal.
6. Sodium is stored in kerosene but Phosphorus under water. Why?
7. What are oxides? Write the nature of metallic and non-metallic oxides.
8. Explain the reactions of metals and non-metals with (i) Acids (ii) Air (iii) Water.
9. What is rust? Write the reaction involved.
10. Do all metals corrode? Explain the corrosion of copper and silver.
Physics
1.Which is easy to drag- a heavy box or light box?
2. Why do we spray powder on carom.
3. What does frictional force produce?
4. Write some factors that affect the friction?
5. How is friction sometimes desirable?
6. Define different types of friction with examples.
7. What is spring balance? Write its construction and working with the help of diagram.
8. Write advantages and disadvantages of friction.
9. Why limiting friction is also known as maximum static friction?.
10.Do liquids and gases also exert pressure?.
11. What is atmospheric pressure? Name the instrument to measure it.
12. We observe that the wheels of buses and trucks are heavier than the wheels of car or scooters. Why?
13. Name the sound producing organ.
14. Can sound travel through vacuum?
15. What is oscillatory motion?
16. What is Ektara? Identify its vibration part.
17. Name three musical instruments and their vibrating parts.
Class 8 Physics
PRESSURE
1. The pressure exerted by air around us is known as __________.
2. Strength of the force is expressed by its ________
3. Force per unit area is called ___________.
4. It is easier to cut with a sharp knife than with a blunt one because ________________________
5. Porters place a round piece of cloth on their heads, when they have to carry heavy loads because _________________________________
6. If a force is applied on a smaller area of contact, the pressure exerted by it is-----------
7. Why do the pillars holding the track of Metro trains have a broader base?
8. Define Pressure. Explain why shoulder bags are provided with broad straps and not thin strap
9. Describe an activity to show that
(i) The pressure exerted by a liquid at the bottom of the container, depends on the height of its column.
(ii) Liquids exert pressure on the walls of the container.
(iii) Liquids exert equal pressure at the same depth.
Answers
Answer:
. The most reactive metal is:
(a) Iron(b) Gold(c) Zinc(d) Potassium.
2. The liquid metal at room temperature
(a) Mercury(b) Bromine(c) Sodium(d) Gold.
3. Non-metals are:
(a) generally liquids(b) generally gases (c) generally solids and gases(d) generally gases and liquids.
4. The metal which is stored in kerosene:
(a) Phosphorus(b) Magnesium(c) Sodium(b) Magnesium
5. The non-metal which is liquid at room temperature is:
(a) Carbon(b) Iodine(c) Bromine(d) Chlorine.
6. Materials around us can be classified into
(a) Elements and compounds(b) Metals and non-metals (c) Acids and bases(d) None of these.
7. All metals are solids except
(a) Sodium(b) Calcium(c) Mercury(d) Hydrogen.
8. Metal oxides are of nature
(a) Acidic(b) Basic(c) Neutral(d) All of these.
9. The metal which can be cut with a knife
(a) Sodium and potassium(b) Barium and calcium (c) Sodium and mercury(d) Potassium and calcium.
10. When non-metals react with water then
(a) Hydrogen gas is formed
(b) Carbon dioxide gas is formed
(c) Non-metals do not react with water
(d) None of these.
Answers
1)d , 2)a , 3)c , 4)c , 5)c , 6)b , 7)c , 8)b , 9)a , 10)c
hope it helps you
Answer:
1= potassium
2= mercury
3= all of above
4= sodium
5=boromine
6 = elements and compounds
7=gallium