Changes

==Key Stage 3=====Meaning===[[File:pHScale.png|right|300px|thumb|A '''pH''' scale with the colours of [[Universal Indicator]] at those '''pH''' values and some examples of [[substance]]s at those '''pH''' values.]]'''pH''' is a scale numbered list from 1 to 14 that is used to identify how [[Acid|acidic]] or [[Base|basic]] a substance is. ===About pH===: '''pH''' is written with a lower case p and an upper case H and refers to the 'power of Hydrogen' as there are free [[Hydrogen]] [[atom]]s in an [[acid]].: [[Acid]]s range from 0-6 on the '''pH''' scale with the strongest [[acid]]s being at '''pH''' 0. : [[Base]]s range from 8-14 on the '''pH''' scale with the strongest [[base]]s being at '''pH''' 14. Remember [[alkali]]s are a [[base]] [[dissolve]]d in [[water]].: '''pH''' 7 is [[Neutral (Chemistry)|neutral]].