Litmus shows if a substance is an acid or an alkali.
Universal Indicator shows how acidic or alkaline a substance is .
This indicator can change to many different colours.
The strength of acids and alkalis is measured on the pH scale.
Universal indicator changes colour and shows the pH of a substance
A pH of below 7 is acidic.
A pH of above 7 is alkaline.
A pH of 7 is neutral