Solids become liquids when the temperature reaches melting point, groups of particles start to brake away from each other. This is when the solid starts becoming a liquid. Liquids become solids on...
water
Water is a gas when it is steam. It condenses to liquid, becoming water. It becomes solid when it freezes, and then becomes liquid again as it melts. The entire process depends on temperature....
Actually, it's really neither. Because nitrogen comes in three forms: it's originally gas, then it's liquid nitrogen, then it gets mixed with others and becomes solid. Although, it's original form is...