Question

4 which pair of arrows correctly represents how the atomic radius of elements changes from lowest to highest on the periodic table of the elements?

Explanation:

The atomic radius of elements increases down a group (as the number of electron - shells increases) and decreases across a period from left to right (due to increasing nuclear charge pulling electrons closer). So, the atomic radius increases from top to bottom and from right to left on the periodic table.

Answer:

The pair of arrows that shows one arrow pointing downwards (to represent increase in atomic radius down a group) and one arrow pointing to the left (to represent increase in atomic radius from right - to - left across a period) is the correct one. Without seeing the actual arrow - pairs in options A, B, C, D, based on the general trend, the correct direction of arrows should be down and left.