<u>Answer:</u> The phase change process in which solids gets converted to gases is sublimation.
<u>Explanation:</u>
For the given options:
<u>Option a:</u> Condensation
It is a type of process in which phase change occurs from gaseous state to liquid state at constant temperature.

<u>Option b:</u> Melting
It is a type of process in which phase change occurs from solid state to liquid state at constant temperature.

<u>Option c:</u> Sublimation
It is a type of process in which phase change occurs from solid state to gaseous state without passing through the liquid state at constant temperature.

<u>Option d:</u> Deposition
It is a type of process in which phase change occurs from gaseous state to solid state without passing through the liquid state at constant temperature.

Hence, the phase change process in which solids gets converted to gases is sublimation.
Answer:
1 mole of atom is correct.
There are non-mercury thermometers with temperature and accuracy rangers equal to most mercury thermometers.
Answer: There are four atoms
Explanation: mass of Cl atom is 35.45 amu
Amount of atoms n = m/M = 142 / 35.45 = 4