What phase change requires a substance to absorb energy? select all that apply. melting freezing evaporation sublimation condensation

When a solid is converted to a liquid, energy must be absorbed. This process is termed as melting.

The reverse process of melting is freezing, where liquid fuses to form a solid. Energy is released in this process.

Evaporation is the conversion of liquid to vapor by absorbing energy.

Sublimation is the direct conversion of solid to vapor state by absorbing energy.

Condensation is the reverse of evaporation. In condensation vapors condense to form liquid releasing energy in the process.

Therefore, the processes that absorb energy are melting, evaporation and sublimation.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.