indicate whether or not each of the following elements can form ions, and if so, give the ion symbol or symbols

Question

a/ silicon
b/ barium
c/ berylium
d/ krypton
e/lead
f/ selenium

Answer 1

a/ Yes. Si4+ (or less commonly Si2+ or Si-4)
b/ Yes. Ba2+
c/ Yes. Be2+
d/ Yes. Kr+ (or less commonly Kr2+)
e/ Yes. Pb2+ (or less commonly Pb4+)
f/ Yes. Se2- (or less commonly Se-4)