2. Mendeleev’s Periodic Table Dmitri Mendeleev

3. Modern Russian Table

4. The Periodic Table Period Group or family Period Group or Family

5. 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:

6. Table of Atomic Radii

7. Table of 1 st Ionization Energies

8. Ionization of Magnesium Mg + 738 kJ  Mg + + e - Mg + + 1451 kJ  Mg 2+ + e - Mg 2+ + 7733 kJ  Mg 3+ + e -

9. 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

10. Table of Ion Sizes

11. Table of Atomic Radii

12. Summation of Periodic Trends