Line Spectra!

Periodic Trends Atomic Size/Atomic Radius

Atomic Radii Atomic radius = ½ the distance between adjacent nuclei (the next closest atom) In non-metals, it is ½ the distance between identical atoms that are bonded

Atomic Radii Trend Decreasing across the periodic table Increasing down the periodic table

Ionic Radius

Cations (+ charge) are always smaller than the neutral atom of the same element – Why? Because we are losing electrons! Anions (- charge) are always larger than the neutral atom of the same element – Why? Because we are gaining electrons!

Ionic radius Size decreases across the periodic table Size increases down the periodic table

Ionization Energy (IE) The energy required (in kJ/mole) to remove an electron from an atom Element A + energy  A + + electron

IE Decreases as you go down a group Increases as you go across the periodic table

Multiple Ionization Energies The energy required to remove the second (or more) electrons! Ex. Sodium (Na) (Element #11) IE 1  496 kJ/mole IE 2  4562 kJ/mole IE 3  6912 kj/mole