## Matter In Our Surrounding Notes and NCERT Solution Class 9 Chapter 1

• November 14, 2020

### Exercise-1.4 Page: 9 ( matter in our surroundings )

1. Convert the following temperature to Celsius scale:

a. 300K          b. 573K

Solution: a.  0°C=273K

300K= (300-273)°C = 27°C

b. 573K= (573-273)°C = 300°C

2. What is the physical state of water at:

a. 250°C         b. 100°C ?

Solution:(a) At 250°C – Gaseous state since it is beyond its boiling point.

(b) At 100°C – It is at the transition state as the water is at its boiling point. Hence it would be present in both liquid and gaseous state.

3. For any substance, why does the temperature remain constant during the change of state?

Solution: It is due to the latent heat as the heat supplied to increase the temperature of the substance is used up to transform the state of matter of the substance hence the temperature stays constant.

4. Suggest a method to liquefy atmospheric gases.

Solution: It can be achieved by either increasing the pressure or decreasing the temperature which ultimately leads to the reduction of spaces between molecules.

Category: Class 9th