Question

Based on the Lewis/electron dot representation
of the two atoms, predict the ratio of metal
cationic (+) atom to nonmetal anionic (-) atom in
the compound.
Be.
•As.
A. 1:3
B. 2:1
C. 3:2
D. 1:1

Answer 1

Answer  the ratio of Be to At is 1:2 in the compound

Explanation:

Be in Periodic Table 2A has 2 valence electrons in its outer orbital and needs to give them away.  When it gets rid of 2 negatives, its charge is +2.

At in Periodic Table 7A has 7 valence electrons in it outer orbitals and needs one more electron.  2 AT atoms each accept one electron from Be and each has a charge of -1.  The Be ion of +2 charge is balanced by the two At ions of -1 charge, so the ratio of Be to At is 1:2