4.2        understand how the pH scale, from 0–14, can be used to classify solutions as strongly acidic, weakly acidic, neutral, weakly alkaline or strongly alkaline

A pH value of 7 is described as neutral.  Anything below 7 is classed as acidic and anything above 7 being classed as alkaline.  The further away from 7 you go, the stronger the acid or alkali.

See Section 4.3 below for colours of Universal Indicator at different pH values.