Question

What are the group trends for atomic radius?

Answer 1

Across a period: `darr`
Down a period: `uarr`

Explanation:

To be honest, the way I remember this is `color(darkblue)("francium (Fr)")`.

Fr has the `color(darkblue)("largest")` atomic radius. Therefore, as you move farther from francium, the smaller your radius will be. If you move closer to francium, the larger your radius.

![https://glossary.periodni.com/

You can see Fr in the bottom left-hand corner. Therefore, if you move across any period from left to right, atomic radius will `color(darkblue)("decrease")` because you're moving farther from Fr.

Going down a period will `color(darkblue)("increase")` your atomic radius because you're moving closer to Fr.