Mendeleev’s Periodic Table Dmitri Mendeleev

Modern Russian Table

The Periodic Table Period Group or family Period Group or Family

Half of the distance between nucli in covalently bonded diatomic molecule "covalent atomic radii" Periodic Trends in Atomic Radius Radius decreases across a period Due to constant shielding with increased nuclear charge. Radius increases down a group Addition of principal quantum levels Determination of Atomic Radius:

Table of Atomic Radii

Table of 1 st Ionization Energies

Ionization of Magnesium Mg kJ  Mg + + e - Mg kJ  Mg 2+ + e - Mg kJ  Mg 3+ + e -

Ionic Radii Cations Positively charged ions formed when an atom of a metal loses one or more electrons Smaller than the corresponding atom Anions  Negatively charged ions formed when nonmetallic atoms gain one or more electrons  Larger than the corresponding atom

Table of Ion Sizes

Table of Atomic Radii

Summation of Periodic Trends