Chemistry

Q.

Give ten examples of each, man-made things or natural things

Q.

What is science?

Q.

At what temperature are Celsius and Fahrenheit equal?

Q.

A gas exerts pressure on the walls of its container because

1. The particles of a gas are static.

2. The particles of a gas react with each other.

3. The particles of a gas hit the walls of the container.

4. Particles of the gas react with the walls of the container.

Q.

What elements do we use in everyday life?

Q.

Write five transparent, translucent and opaque objects.

Q. Who is known as Father of chemistry? Why ?​

Q.

During daytime plants take in oxygen and give out carbon dioxide, during the night it is vice-versa.

1. True
2. False

Q.
Give reason why a wooden table should be called a solid.

Q. The chemical formula of Plaster of Paris is:

1. $CuS{O}_4.5H_{2}O$
2. $CaC{O}_3$
3. $N{a}_{2}C{O}_3$
4. $CaS{O}_4.1/2H_{2}O$

Q.

What are the different types of gases present in air and what is the percentage of the different gases which are present?

Q.

Write $5$ things which dissolve in Water and Which do not dissolve in Water.

Q.

How will you separate oil and water from their mixture?

Q.

6. Give five examples each of objects that float and sink in water.

Q. Write any five properties of air.

Q.

Give two examples of each of the three states of matter: solid, liquid, and gas.

Q.

List the points of differences between homogeneous and heterogeneous mixtures.

Q. Name five plants and their part that we eat.

Q.

Why is carbon dioxide a non-polar molecule, even though the C-O bonds are polar?

Q.

What are the factors that affect the weather?

Q.

Why does solubility of gases increase with decrease in temperature?

Q.

What is the end product of photosynthesis?

Q. Why is soil considered one of the most important natural resources?

1. Soil is the base for agriculture

2. Soil provides us with plastics

3. Soil is used to make earthen pots

4. Soil helps in killing bacteria

Q. Metal react with water to form metal oxide and hydrogen gas. Give reasons

Q.

Give one example of a homogeneous mixture.

Q. Smog is a mixture of:

1. Smoke and Fog
2. Smoke and dust particles
3. Dust particles and water droplets
4. Fog and water droplets

Q.

Define the term element?

Q. Which of the following gas is used in fire extinguisher?

1. Oxygen
2. Carbon dioxide
3. Helium
4. Hydrogen

Q. How can we conserve soil? [3 MARKS]

Q.

What is mole percent? Give an example