Answer:
Ba3N2
Explanation:
Barium is a metal element and Nitrogen is a non-metal element, so they forme an ionic compound. To make the formula of an ionic compound, first we need to see the valence of the atoms, that is, how much electrons it can donate or it has to gain to have 8 electrons in the valence layer (octet rule).
Barium is in the family 2, so it has two electrons in its valence layer, so it must donate these two electrons; Nitrogen is in the family 15, so it has 5 electrons ins its valence layer and must gain 3 electrons.
Writing the ions they must form:
[tex] Ba^{+2} N^{-3}] [/tex]
First came the cation (positive charge), then the anion (negative charge), and the charges must change between them, without the signal, and will inform how many atoms are necessary of which element:
Ba3N2
