Physical change does not make a new chemical/object. A chemical change does.
Chemical Change example: Combining liquid and liquid to create a new substance
H20 and c20 were brothers and sisters before ch3ch2nh2 even existed
A pH of 7 is neutral, because a measure of acidity or alkalinity of water soluble substances (pH stands for 'potential of Hydrogen'). A pH value is a number from 1 to 14, with 7 as the middle (neutral) point.