(01.05 lc)
when heat energy is added, two changes are observed:
change a: solid changes phases to a liquid.
change b: liquid changes phases to a gas.
what are the names for phase changes a and b?
a is freezing and b is evaporation.
a is freezing and b is condensation.
a is melting and b is evaporation.
a is melting and b is condensation.

Option (c) is the correct answer.

Explanation:

Melting is defined as the process in which a solid phase of a substance changes into liquid phase. And, a process in which liquid state of a substance changes into gaseous phase.

When we heat a solid substance then its molecules absorb heat energy and bonds between its atoms tend to break down. As a result, molecules gain kinetic energy and solid changes into liquid state.

Upon further heating, more kinetic energy is gained by molecules of a liquid. As a result, liquid changes into vapors or gaseous state.

Thus, we can conclude that the names for phase changes A and B are A is melting and B is evaporation.

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.