C2 The Periodic Table

C2 The Periodic Table

Development of the periodic table

• Dalton arranged the periodic table in order of atomic weight. 
• Newlands found a pattern in every eighth element - the law of octaves.
• Mendeleev put them in groups, left gaps for undiscovered elements, and changed the order where the rules didn't apply.

What does group number tell?

It tells you the number of electrons in the outer shell.

What are the properties of metals and non-metals?

Non-metals are brittle and non-conductors; metals are malleable, conductors, and have a high boiling point.

The properties and patterns in Group 1

• Low density
  
• Soft
• Reactive
• As you go…