Which of the following represent(s) an exothermic process

A. The liquid undergoes as the particles speed up and become a gas

B. When energy from the surroundings is absorbed into the system

C. The process a piece of metal undergoes when it is at 100 degrees celsius and then placed in water that is at 24.5 degrees celsius

D. The process a chemical undergoes when the bonds break during a chemical reaction

C

Explanation:

It is C because heat naturally goes towards areas of lower heat, thus exothermic

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

i would say b

explanation:

but i think i would need more information than that