Final answer:
Elements from group 2 of the periodic table combine with elements from group 16 in a 1:1 ratio to form chemically stable compounds, balancing their +2 and -2 charges respectively.
Step-by-step explanation:
Based on the periodic table, elements from group 2 (the alkaline earth metals) typically have a +2 charge as they tend to lose two electrons to have the same number of electrons as the nearest noble gas.
On the other hand, elements from group 16 (also known as the chalcogens) typically have a −6 charge because they tend to gain two electrons to achieve a full outer shell. Therefore, when elements from group 2 combine with elements from group 16, they form a compound with a ratio that balances these charges.
The correct ratio for the combination of group 2 and group 16 elements is 1:1. A group 2 element with a +2 charge will combine with a group 16 element with a -2 charge in such a way that each group 2 atom pairs with one group 16 atom to neutralize the charges. This results in a chemically stable compound.