1. History of the Periodic Table
1808: Dalton’s Table of Elements
Order of mass
Measured in chemical reactions
1863: Newland’s Law of Octaves
Every 8th element seemed similar
Two elements in the same box so everything fit
Assumed all elements had been discovered
1862: Chancourtois
Better than Newland’s
Every 8th element similar
Published his work without the diagram so everyone was confused!

2. Left gaps for new elements that had not yet been discovered
Order of atomic mass
Predicted new elements’ properties from his table – and was right when they were discovered!
Left gaps for new elements that had not yet been discovered
1869: Dmitri Mendeleev

3. Good conductors of electricity and heat due to free electrons
halogens
All look different at room temperature F Cl Br I At
F-F
Cl-Cl
Br-Br
I-I
Melting point (°C)
-220
-101 -7
114
Boiling point (°C)
-188
-35 59
184
Transition Metals
Good conductors of electricity and heat due to free electrons
Can be used to make alloys – mixed with other elements to create a stronger material
All form coloured compounds due to inner electron shell between groups 2 and 3

4. Transition metals cont.
List 5 properties of metals below:
Complete the following sentences using the words below:
The transition metals are a block of elements that lie between Groups …… and …… in the periodic table. These elements nearly all have high ……………………, high ………………………… points and are good ………………………… . They are ………………………… reactive than the alkali metals, and often form …………………… compounds.
Match the metal with the correct coloured compound
Iron II
Iron III
Copper
Potassium
Chromium
We use these coloured compounds as pottery glazes,
or just to give colour to buildings (e.g. copper roofs or statues!)
Green
Blue
Reddish-brown
Purple
Orange