Chemistry Coulter 4th

Periodic Trends

1.     Ionization Energy: the energy required (necessary) to remove an electron from an atom or ion.

Example: Na by it’s self is very reactive…1s²2s²2p⁶3s¹

Valence electrons: 1

If you take the valence electron away…

If the Shell is full it is stable.

A. The First Ionization Energy: The amount of energy required to remove the 1^st electron

2.     Atomic Radius

3.     Electronegativity

4.     Electron Affinity

Octet:

·      8 electrons in the outer shell = a very stable atom

·      (full set of electrons in the outer shell)

Explain why each successive ionization of an electron requires a greater amount of energy… Successive ionization energies increase in magnitude because the atom from which the electron is removed becomes progressively more positively charged!!!!!! (THE ELECTRON IS ATTRACTED TO THE NUCLEUS)

•        The ionization energy of the elements within a period generally increases from left to right. This is due to valence shell stability.

•        The ionization energy of the elements within a group generally decreases from top to bottom. This is due to electron shielding.

•        The noble gases possess very high ionization energies because of their full valence shell as indicated in the graph.

•        Note that Helium has the highest ionization energy of all the elements.

As it goes down.. it is easier to remove an electron

If you move across (to the right) it is harder to remove an electron.

FINISH IN CLASS: YASMINE DO FOR HOMEWORK

Pg 198-199: 43, 44, 45, 64