– Water exists in 3 states:
Solid/ice, liquid/drinking water, gas/water vapor.
Melting point = freezing point. They both describe the same transition of matter – liquid to solid is freezing and solid to liquid is melting.
Freezing point of water — 32 F and 0 C at 1 atm of pressure
Boiling point of water — 212 F and 100 C at 1 atm of pressure

– What is pH? pH measures acidity in liquid solutions.
pH 1-6 is acidic. 7 is neutral. 8-14 is basic.

– Proton: +1 charge, neutron: 0 charge, electron: -1 charge