Which of the following statements is true about the periodic table? the atomic radius increases moving down a column. the atomic radius decreases moving down a column. the chemical reactivity of metals increases moving from left to right. the chemical reactivity of nonmetals decreases moving from left to right.

option (a) is the correct answer.

Explanation:

In a periodic table, when we move from top to bottom in a periodic table then there will be increase in number of shells because of addition of more number of electrons.

As a result, there will be increase in atomic radius of the atom.

Metals are the elements which have excess of electrons but on moving from left to right in a periodic table reactivity of metals decreases as there valence shells does not contain extra electrons to donate.

On the other hand reactivity of non-metals increases on moving from left to right.

Hence, we can conclude that the statement atomic radius increases moving down a column, is true about the periodic table.

the answer is d.) potassium