What kind of electrons are involved in chemical bonding?

What are the first three quantum numbers for the electrons located in subshell 2s?

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?