Question

Give the trend for atomic radius across a period and down a group, and explain each of these trends in terms of attraction, repulsion, and effective nuclear charge.

Answer 1

Atomic radius decreases across a group because you are gaining protons and electrons there for making the attraction greater and making them more tightly held. As you go down a group you arent increasing the Zeff you are really just making it bigger.

Answer 2

across a group lol a period sorry