1. The Periodic Table

2. S/L/G at room temp, non-metallic, v. reactive (esp. with hydrogen)
Group
Name
Properties 1
Soft, silver-coloured, solids at room temp, react strongly with H2O, stored in mineral oil (to prevent reacting with O2) 2
Light, metallic properties, react with O2 to form oxides, solids at room temp 7
S/L/G at room temp, non-metallic, v. reactive (esp. with hydrogen) 8
G at room temp, low MP/BP, v. unreactive
Alkali metals
Alkaline metals
Halogens
Noble gases

3. You can calculate the # of neutrons by:
The atomic number (Z) is also the # of protons for an atom of that element
The mass number (A) is the sum of the sub-particles in an atom (protons + neutrons). Note – electrons weigh virtually nothing, so they are not included. The # of electrons is the same as the # of protons!
You can calculate the # of neutrons by:
# neutrons = A – Z

4. Mass Number (bigger)
ZAX
symbol
Atomic Number (smaller)

5. Ca 20 40 Sn 119 50 20 20 20 50 69 50 Element Atomic Number Atomic Mass
# Protons
# Electrons
# Neutrons Ca 20 40 Sn
119 50 20 20 20 50 69 50

6. Isotopes
The same atom with a different atomic mass. The atomic number, and therefore the number of protons and electrons in the atom, does not change
Eg. Carbon can be carbon-12 and carbon-13.
Some isotopes are more abundant (common) than others.

7. Calculating Average Atomic Mass
(Atomic mass x % Abundance)Isotope 1 +
(Atomic mass x % Abundance)Isotope 2
Note: Convert % abundance into decimal value
(eg. 75% = 0.75)

8. Example 1 Carbon-12 has atomic mass of and % abundance of Carbon-13 has atomic mass of and % abundance of 1.10 Av. AM = ( )(0.9810) + ( )(0.0110) = u

9. Example 2 Natural neon consists of three stable isotopes: neon-20 (90
Example 2 Natural neon consists of three stable isotopes: neon-20 (90.48%), neon-21 (0.27%), neon-22 (9.25%). Calculate the average atomic mass of neon. Av. AM = (20)(0.9048) +(21)(0.0027) + (22)(0.0925) = u

10. Trends in the Periodic Table
Atomic Radius
Distance from center of atom to edge
Ionization Energy
The energy required to remove one electron from that atom

12. Increasing Ionization Energy

13. Trends in the Periodic Table
Electron Affinity
Energy change that accompanies the addition of an electron
Electronegativity
A number; the tendency of an atom to attract an electron

14. Increasing EN and EA