As the lauric acid was melting, heat was being added to it but the temperature did not rise. Where did the heat energy go?

During the phase change, when solid melts into liquid, its temperature remains constant as the heat energy is stored as potential energy. Likewise, as heat is added to a liquid, its temperature increases as the molecules, once again, move faster.

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.

the awnser is group 12