PLEASE HELP ME ASAP What volume (mL) of concentrated H3PO4 (14.7 M) should be used to prepare 125 mL of a 3.00 M H3PO4 solution.

Most likely a is the answer - because  you generate   38 atp's but also consume an atp.   each atp gives approx. less than 4 kcal so probably a is the closest answer.

The mass has escaped into a gas which you can not see so the law stays true.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom