Which arrows represents the phase transitions in which he's energy is gained

The correct option is 1, 2 and 3.

Explanation: There are 3 phases of matter.

1) Solid

2) Liquid

3) Gas

The phase transitions between these phases will require some amount of heat energy or will release some amount of heat energy.

The phase transition from solid to liquid will require heat because the bonds between the particles are to be broken. Hence, some amount of heat energy is required. This process is known as Fusion. Arrow representing this process is 1.The phase transition from liquid to gas will require heat because the bonds between the particles are to be broken. Hence, some amount of heat energy is required. This process is known as Evaporation. Arrow representing this process is 2.The phase transition from solid to gas will require heat because the bonds between the particles are to be broken. Hence, some amount of heat energy is required. This process is known as Sublimation. Arrow representing this process is 3.The phase change from gas to liquid will release some heat because the bonds between the particles are to be formed. Hence, some amount of heat energy will be released. This process is called as Condensation. Arrow representing this process is 4.The phase change from liquid to solid will release some heat because the bonds between the particles are to be formed. Hence, some amount of heat energy will be released. This process is called as Freezing. Arrow representing this process is 5.The phase change from gas to solid will release some heat because the bonds between the particles are to be formed. Hence, some amount of heat energy will be released. This process is called as Deposition. Arrow representing this process is 6.

Hence, the arrows 1, 2 and 3 represent the phase transitions which require heat energy.