Why do beryllium and fluorine combine in a 1:2 ratio?

Question

use page 194 in your textbook.

Be is in group 2 (IIA) and has two electrons in its outer shell which it wants to give away. Flourine is in group 17 (VIIA) and has seven electrons. It needs one more to fill its outside shell. So two F atoms are needed per one Be

Answer 1

Because beryllium has two plus charge and fluorine has a one minus charge to make the two have property, you'll need 1Br and 2F which would then be BeF2.

Answer 2

Ionic compounds