Definition:
The distance from the nucleus to the edge of the outermost electron cloud. In this trend, the largest atoms are low and left, and the smallest are high and right.
Trends:
The atomic radius increases down a group. This is because as the energy level is increasing, so is the distance from the nucleus.
The atomic radius decreases across a period. This is because as you go across, more protons are being added on and they pull the electrons closer to the nucleus.
Extra:
Along with the atomic radius are covalent, ionic, and metallic radii.
Covalent radius can be determined between two atoms covalently bonded together. If two of the same element are bonded together, the radius would be halfway between the two nuclei for each atom, due to the equal attraction of electrons.
Ionic radius is measured within an ionic bond or ion. Anions will have a larger radius than their neutral atom, and cations will have a smaller radius.
Metallic radius is present in an atom joined by a metallic bond. The radius would be half of the total distance between the nuclei of two atoms in a metallic cluster.
The distance from the nucleus to the edge of the outermost electron cloud. In this trend, the largest atoms are low and left, and the smallest are high and right.
Trends:
The atomic radius increases down a group. This is because as the energy level is increasing, so is the distance from the nucleus.
The atomic radius decreases across a period. This is because as you go across, more protons are being added on and they pull the electrons closer to the nucleus.
Extra:
Along with the atomic radius are covalent, ionic, and metallic radii.
Covalent radius can be determined between two atoms covalently bonded together. If two of the same element are bonded together, the radius would be halfway between the two nuclei for each atom, due to the equal attraction of electrons.
Ionic radius is measured within an ionic bond or ion. Anions will have a larger radius than their neutral atom, and cations will have a smaller radius.
Metallic radius is present in an atom joined by a metallic bond. The radius would be half of the total distance between the nuclei of two atoms in a metallic cluster.