False. Think about how teachers have air conditioners on the top of the windows and how air balloons float up!! Therefore warm hair is lighter then cold air.
The correct solution for this is explained the first option. Since water has an equivalent amount or number of H ions and OH ions, pure water itself is not slightly acidic nor basic. This equality of ions, causes the pH of water to be around the mid point of the pH scale which goes from 0 - 14, and thus is 7. This is a neutral pH.
When a bend in a river gets cut off...