• Starter:

1)Describe how the reactivity changes in group 7.

2)Cl2 + KBr→

3)What type of bond do halogens form with metals?

4)Why do halogens exist as diatomic molecules?

The transition elements

L.O.:

Recall properties of the transition elements.

Where are the transition metals?

The transition metals are the block of elements located between group 2 and group 3 of the periodic table.

Ac Rf Db Sg Bh Hs Mt Ds Rg

La Hf Ta W Re Os Ir Pt Au Hg

Y Zr Nb Mo Tc Ru Rh Pd Ag Cd

Sc Ti V Cr Mn Fe Co Ni Cu Zn

?

Here, the word ‘transition’ is used to mean ‘in-between’.

group 2 group 3

Why are they called the ‘typical metals’?

There are over 30 transition metals.

The transition metals are known as ‘typical’ metals. Why do you think this might be?

They include most of the metals we are familiar with and use everyday, such as iron, copper and gold.

However, there are many transition metals that are less familiar to us, because they are very rare or have few uses.

The transition metals are known as ‘typical’ metals because of their physical properties. They are:

What are the properties of the transition metals?

lustrous (bright and shiny).

high density.

good conductors of heat and electricity.

high melting and boiling points (except mercury, which is liquid at room temperature).

hard and strong.

malleable (can be bent and pressed into different shapes) and ductile (can be drawn into wires).

Comparing properties of different metals

How do the properties of transition metals compare with those of alkali metals?

are more dense. This means that in a fixed volume of metal there are more atoms of a transition metal than there are of an alkali metal.

have higher melting and boiling points – except mercury.

are harder and stronger. They cannot be cut with a knife.

Compared to the alkali metals, the transition metals:

Comparing densities of metals

Comparing melting points of metals

True or false?

Transition metal compounds and colour

Most transition metals form coloured compounds.

Copper (II) sulfate crystals (CuSO4.H2O) is blue – these can be turned white by heating the crystals to remove the water.

Iron (III) oxide (Fe2O3) is red/brown – when hydrated this is rust.

Iron (II) oxide (FeO2) is black.

For example:

Uses of coloured tm compounds

The coloured compounds of transition metals can also be used in many ways, for example:

as coloured glazes on pottery.

to colour paints

to colour stained glass windows

The colour of many gemstones comes from the presence of transition metal compounds. For example, the gemstone jade contains iron.

• Electronic arrangement of transition metals:

• 2, 8, , 2

The third shell can have 18 electrons.

The third shell is fill after the fourth shell.

• Task:

Workbook page 109 &110