Periodic law states that when the elements are arranged according to their atomic numbers, this allows elements with similar properties to appear at regular intervals. predict the group of elements and their number of valence electrons that will combine in a 3: 2 ratio to with calcium. a) boron, aluminum, gallium; 3 b) sulfur, selenium, polonium; 6 c) oxygen, tellurium, bismuth; 2 d) nitrogen, phosphorus, arsenic; 5

The correct answer is Option D.

Explanation:

Calcium is the 20th element of the periodic table having electronic configuration

This element will loose 2 electrons easily to form stable configuration. This is a metal and will form an ionic bond with a non-metal.

From the given options:

Option A: boron, aluminum, gallium; 3

These elements belong to Group 13 and are considered as metals having oxidation state of +3 because they easily loose 3 electrons. Thus, they will not form any compound with calcium.

Option B: sulfur, selenium, polonium; 6

These elements belong to Group 16 and are considered as non-metals having oxidation state of -2 because they easily gain 2 electrons. Thus, they form compound with calcium but in a 1 : 1 ratio.

Option C: oxygen, tellurium, bismuth; 6

These elements belong to Group 16 and are considered as non-metals having oxidation state of -2 because they easily gain 2 electrons. Thus, they form compound with calcium but in a 1 : 1 ratio.

Option D: nitrogen, phosphorus, arsenic; 5

These elements belong to Group 15 and are considered as non-metals having oxidation state of -3 because they easily gain 3 electrons. Thus, they form compound with calcium in a 3 : 2 ratio.

Hence, the correct answer is Option D.