Some Important Groups in the Periodic Table

Elements in the same group have the same number of outer electrons and similar chemical properties.

Group 1 - The Alkali Metals

The elements in group 1 are known as the alkali metals. They react rapidly (very quickly) with water, producing an alkaline solution and hydrogen gas.

As you go down the group the elements become more reactive.

Examples include lithium and sodium.

These metals are stored under oil because they are highly reactive. They are soft, light metals. The reactions of the alkali metals are shown below:

Group 2 - The Alkaline Earth Metals

These elements include magnesium and calcium.

They burn brightly and react with oxygen to form oxides.

The oxides form alkaline solutions with water. For example:

magnesium + oxygen --> magnesium oxide

magnesium oxide + water --> magnesium hydroxide

Magnesium hydroxide is an alkaline solution.

Group 7 - The Halogens

The elements in group 7 are known as halogens.

Fluorine and chlorine are gases. Bromine is one of only two liquid elements. Iodine is solid.

As you go down the group the halogens become less reactive.

Group 0 - The Noble Gases

The elements in group 0 are called the noble gases.

They are very unreactive and exist as individual atoms (monatomic).

Examples include: helium and neon.

Remember: Elements in the same group have the same number of outer electrons and similar properties.

The Transition Metals

The transition metals are elements which are found between groups 2 and 3. They do not have their own group number.

Well known examples are iron, copper and gold.

They are generally quite dense (heavy) and many form brightly coloured compounds.

Next section: Chemical Formulae