1. 5.2 Electron Configuration and the Periodic Table

2. Blocks
The blocks of the table are determined by the sublevels being filled by electrons.
The location of an element on the table can be determined by its electron configuration.

3. Identify the element 3p3 7s1 4d6 5p5 3d3 Phosphorus Francium Ruthenium
Iodine
3d3
Vanadium

4. Alkali metals Group 1 Configuration ends in ns1 Reactive metals
Form +1 cations
Not found free in nature
React with water to form hydrogen gas
Stored to avoid contact with air and water.

5. Alkaline Earth Metals Group 2 ns2
Harder, denser, stronger than group 1
Higher melting points
Less reactive – but still not found free in nature.

6. Hydrogen
Unique element – not member of any family
ns1

7. Transition Elements
The d-block elements with good metallic properties.
Deviations occur in some electron configurations.
Less reactive than groups 1 and 2
Groups 3-12

8. Main group elements
S block + p block

9. Metalloids Also called semimetals. B, Si, Ge, As, Sb, Te
Properties of both metals and non-metals.

10. Halogens Group 17 ns2np5 Most reactive non-metals
React with metals to form salts

11. Noble Gases
Group 18
Unreactive
ns2np6