The general trend is a decrease in size as you move from left to right . This is apparent in periods 2 and 3 but in period 4 and above we have the transition metals and these have some exceptions.
This is due to the fact that as we moves from left to right along a period while the nuclear charge increases we are also adding extra electrons but the effective charge is mainly affected by the inner core electrons that "shield" the outer electrons. The effective nuclear charge, the charge felt by the outer electrons, increases across a period thus causing a contraction in the shell.
The general trends are:
- in a group: atomic radius increasing down
- in a period: atomic radius decreasing to right
Also the atomic radius depend on the atomic number - increasing radius with increasing atomic number; but some irregularities exist.
it increases in radius while moving from the top of a group to the bottom and decreases in radius while moving across a period, from left to the right.
Decrease
atomic radii increases from left to right in the periodic table from metal to non metal in the right
group 1 elements
Across a period the atomic size decreases. Hence elements in the right side of the periodic table have small size / radii.
Fluorine has the smallest atomic radii because it is towards the right of the periodic table and on top.
As you move across a row on the periodic table, the atomic radii becomes smaller due to the attraction between positive protons and negative electrons. As you move down a column, the radii increase due to the addition of valance electrons.
Atomic Radii,Ionic Radii, First Ionization Energy,Second and Higher Ionization Energies, Electron Affinity.
Look for a reference chart in a book or online. Look for a Periodic Table of the Elements that has the atomic radii on it.
atomic radii increases from left to right in the periodic table from metal to non metal in the right
group 1 elements
The atoms with the largest atomic radii are found in the lower right side of the periodic table. Smallest atoms are found in the higher left part of the periodic table. He has the smallest atomic radii.
Across a period the atomic size decreases. Hence elements in the right side of the periodic table have small size / radii.
Generally increase
Atomic radii decreases on moving from left to right as the effective nuclear charge increases.
The elements with the smallest atomic radii are found in the top of the P block of the periodic table. Helium (He) has the smallest atomic radius. Francium, on the other side of the periodic table (very bottom of the S block), has the largest atomic radius.
Fluorine has the smallest atomic radii because it is towards the right of the periodic table and on top.
As you move across a row on the periodic table, the atomic radii becomes smaller due to the attraction between positive protons and negative electrons. As you move down a column, the radii increase due to the addition of valance electrons.
As more energy levels are occupied by electrons, the atomic radius gets larger.