why irons melting point is so much higher than water, and why nitrogens is so much lower then either of them?

Question

why is irons melting point is so much higher than water and why nitrogens is so much lower than either of them 

Answer 1

Melting point depends on the force of attraction between molecules. Melting requires heat energy, but the amount necessary to jiggle the atoms enough to change their state of matter varies based on the attraction between molecules. Water's molecules are not as strongly attracted to each other as are iron's, and nitrogen's are even less strongly attracted.