What best explains the formula unit for a compound made from nitrogen and hydrogen?

nh4, because nitrogen needs four electrons, and each hydrogen needs one electron.
nh4, because nitrogen needs one electron, and each hydrogen needs four electrons.
nh3, because nitrogen forms a single bond with each hydrogen atom.
nh3, because nitrogen forms a triple bond with each hydrogen atom.

Construct the hypothetical phase diagram for metals a and b between room temperature (20c) and 700c, given the following information: * the melting temperature of metal a is 480c. • the maximum solubility of b in a is 4 wt% b, which occurs at 420c. • the solubility of b in a at room temperature is 0 wt% b. • one eutectic occurs at 420c and 18 wt% b–82 wt% a. • a second eutectic occurs at 475c and 42 wt% b–58 wt% a. • the intermetallic compound ab exists at a composition of 30 wt% b–70 wt% a, and melts congruently at 525c.• the melting temperature of metal b is 600c. • the maximum solubility of a in b is 13 wt% a, which occurs at 475c. • the solubility of a in b at room temperature is 3 wt% a.

Draw the skeletal structures of two different molecules that are each made of 5 carbon atoms and 12 hydrogen atoms.

Which of the following electromagnetic waves can create ions?