Question

Based on the periodic table, elements from group 2 and 16 will combine in which ratio? (group 2 to 16)

a. 1:2
b. 1:1
c. 2:3
d. these elements will not combine.

Answer 1

Elements from group 2 and group 16 combine in a 1:1 ratio to form an electrically neutral compound, with each group 2 element providing two electrons to fulfill the two-electron gap for each group 16 element. Option B is correct.

Step-by-step explanation:

Elements from group 2 (the alkaline earth metals) have a valency of +2 because they can lose two electrons to achieve a full outer shell.

Elements from group 16 (also known as the chalcogens) have a valency of -2 as they tend to gain two electrons to fill their outer shell. When these two groups combine to form a compound, they do so in a way that the total charges balance out.

Therefore, one element from group 2 will combine with one element from group 16 in a 1:1 ratio to neutralize the charges, resulting in an electrically neutral compound. This can be visualized with the cross method (as shown in the provided materials), which would show a 2+ charge cross-bonding with a 2- charge, simplifying to a ratio of 1:1.