Answer:
Endothermic. Endothermic phase changes take in heat from the surrounding environment; they include melting, sublimation and boiling. ... For example, the forces that hold iron atoms together are strong, so it takes high temperatures to melt iron.
Explanation:
There's two sig figs: the 1 and the zero. The 10^-2 contributes no sig figs.
(2C+2+N-X-H)/2
(2*7+2+0-0-8)/2
4