Atomic Radius

[noree_jauregui]

Why does the radius get smaller as you go upwards and to the right of the periodic table if there are more electrons in the orbitals?

[106036120]

Atomic radius increases as you go down and to the left. Going down there are electrons filling up the outer energy shells so it gets bigger. Even though there are more electrons in the atom as you go to the right, there are also more protons. More protons means that there is more positive attraction pulling the electrons in.

For example both Oxygen and Fluorine have electrons in the 2p orbital, but fluorine has more protons which can pull its electrons in closer.

[Wenting_2F]

As you move from left to right across a period, the number of protons in the nucleus increases. This results in a stronger nuclear charge, attracting the electrons more strongly. Although the number of electrons also increases, they are being added to the same energy level, not creating much additional shielding. The increased nuclear charge pulls the electrons closer, reducing the atomic radius.

[Eman Almuti 3H]

the general trend for atomic radius is:

decreases across the period
increases down the group

if you are going upward in the group, regardless of whether its on the right or left side of the periodic table, the atomic radius will decrease. this because down a group the number of electron shells increases and, therefore, the radius is larger.