Skip to content
Interactive Resources for Schools
Schools Search Icon

Content

Help and information

This topic takes on average 30 minutes to read.

There are a number of interactive features in this resource:

Topic last updated: 26 Oct 2023

You may also be interested in these related topics

    • Ico Science Science
    • Ico Chemistry Chemistry
    • Biology Biology
    • 11-14
    • 30

Acids, alkalis and acid rain

  of  2

The pH scale

The pH of the water on the Earth is important for maintaining life. All substances will be acidic, neutral, or alkaline, and we use the pH scale to determine this.  

Different people may need to measure the pH, like a scientific or environmental researcher, and they can use a pH meter which will give the pH as a number.  

Alternatively, an indicator can be used such as ‘universal indicator’ which can be added to the substance and will change colour.  

Either the colour or the number can be compared to the pH scale to work out if a substance is acidic, neutral or alkaline.  

pH scale

Pure water is neutral, though oceans have a pH of around 8 making it mostly neutral but ever so slightly basic. 

Global warming and pH balance
Next