Question

I dont understand how to find the one with smallest atomic radiusa. Calciumb. Cobaltc. potassiumd NickelI think its last one but why

Answer 1

d. Nickel

Step-by-step explanation:

The atomic radius is a periodic property, that is, we can see how it varies in the Periodic Table of Elements.

Atomic radius increases by a column (group) from top to bottom, and increases by a row (period) from right to left.

We can see the variation of atomic radius and the location of the given atoms in the following drawing:

Since K (potassium), Ca (calcium), Co (cobalt) and Ni (nickel) are located in the same row (period), to identify which one has the smallest atomic radius, we have to analyze the increase in horizontal atomic radius.

So, the Ni atom has the smallest atomic radius (because it is located more to the right compared to the other atoms in the same row) and K atom has the largest atomic radius.