Question

Within a family: the atomic radius will increase as you go down. Why?

Answer 1

The atomic radius increases as you go down within a family and decreases as you go across a row on the periodic table.

Step-by-step explanation:

Within a family, the atomic radius increases as you go down because the valence electron shell gets larger and there is a larger principal quantum number, causing the valence shell to lie physically farther away from the nucleus. This trend can be summarized as the atomic radius increases from top to bottom within a group.

On the other hand, going across a row on the periodic table from left to right, the atomic radii decrease. This is because the increasing positive charge of the nucleus casts a tighter grip on the valence electrons, pulling them closer to the nucleus.

Answer 2

This is caused by the increase in the number of protons and electrons across a period. One proton has a greater effect than one electron; thus, electrons are pulled towards the nucleus, resulting in a smaller radius. Atomic radius increases from top to bottom within a group. This is caused by electron shielding