Question

Нитрид металла 1-Ca3N2 2-Mg(OH)2 3-CaH2 4-H2BeO2

Answer 1

Нитрид металла - 1) Ca3N2(нитрид кальция)

Answer 2

The correct notation for the metal nitrides you provided is as follows:

1. Ca3N2 (Calcium nitride)
2. Mg(OH)2 (Magnesium hydroxide) - This is not a metal nitride.
3. CaH2 (Calcium hydride)
4. H2BeO2 (Beryllium hydroxide) - This is not a metal nitride.

Only option 1 (Ca3N2) and option 3 (CaH2) are metal nitrides. The others are different chemical compounds.