Question

Complete the following sentences: 1. The phase change in which a substance changes from a liquid to a gas is ______.

Answer 1

Answer: 1.  d. vaporization

2. b. melting

3. a. sublimation

Explanation: There are three states of matter, namely solid , liquid and gas.

In solid the particles are closely packed as the inter molecular forces of attraction are strongest. as they are heated, the kinetic energy of the molecules increases and thus the molecules start moving farther and convert to liquid state. The process is called melting.

When liquid is further heated, the molecules gain more kinetic energy and molecules move farther and convert to gaseous state and the process is called vaporization.

When a solid directly converts to gaseous state without changing into liquid first is called sublimation. Example: Napthalene

Answer 2

1. The phase change in which a substance changes from a liquid to a gas is condensation. The correct option among all the options given is option "c".

2. The phase change in which a substance changes from a solid to a liquid is melting. The correct option among all the options given is option "b".

3. The phase change in which a substance changes from a solid to a gas or vapor without changing to a liquid first is sublimation. The correct option is option "a".