Gas to solid ( a ) is correct i think
The number of chirps increases in relation to temperature.
Refer to picture attached for solution
If I understand this right, the two elements are Nickel and Copper, elements 28 and 28, respectively. A nickel is worth 5 cents, and a penny, originally comprised of copper, is worth one - the total being six cents.
Boiling or also called evaporation is the conversion of liquid to gas through the application of heat. This phase change is an endothermic change and is the opposite of condensation from gas to liquid.
