Chemicals also feature heavily in our foods. For example, acids are what make oranges and lemons taste sharp and tangy, and are present in vinegar and fizzy drinks.

Alkaline substances in the home, on the other hand, include baking soda, soap, milk of magnesia and ashes.

A lot of people probably do not realise that this situation allows for useful chemical reactions. For example, when acids and alkalis are mixed they counteract each other which is why, for example, since bee stings are acidic, some people recommend putting baking soda on the affected area.