Quick Answer: Why Does Atomic Size Increase Down A Group And Decrease Left To Right?

Why does atomic size decrease from left to right?

Atomic size gradually decreases from left to right across a period of elements.

This is because, within a period or family of elements, all electrons are added to the same shell.

The valence electrons are held closer towards the nucleus of the atom.

As a result, the atomic radius decreases..

Why do both atomic size and ionic size increase as you move down a group?

Basically, as we move down the periodic table, the size of the nucleus increases, and concomitantly more electrons are present to “shield” the valence electrons from the charge. … If there are many electrons, its harder to rope them up via electron charge than when there are less.

Do electrons determine the atom’s size?

Electrons determine the atom’s size. … With electrons on the surface, atoms repel one another when they come too close. Thus, electrons determine the space that an atom occupies.

Does Zeff increase down a group?

The effective nuclear charge, Zeff, increases down a group which draws electrons closer towards the nucleus, decreasing atomic radius.

Why does atomic size increase down a group?

In general, atomic radius decreases across a period and increases down a group. … Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital. This results in a larger atomic radius.

How does the atomic size vary on moving down a group?

On moving down the group, from top to bottom, the atomic size increases. This is because with increase in the atomic number, extra shells of electrons are added.