Answer: See below
Step-by-step explanation:
Sodium (Na) - 1 electron on outer shell so would need to lose 1 electron for a full outer shell - making it a 1+ ion
Surfur (S) - 6 electrons on outer shell so would need to gain 2 electrons for a full outer shell - making it a 2- ion
Strontium (Sr) - 2 electrons on outer shell so would need to lose 2 electrons for a full outer shell - making it a 2+ ion