Enthalpy represents:
group of answer choices
o the amount of heat absorbed or released by a system at constant pressure.
o the amount of work energy absorbed or released by a system.
o the total energy change (both heat and work) involved in a change.
o the amount of energy inside a system at constant pressure.

The correct answer is: the amount of heat absorbed or released by a system at constant pressure.

Explanation:

Enthalphy is a thermodynamic property and it is often symobolized with the letter H. It is defined as the amount of energy which can be released in form of heat in a process at constant pressure. The variation of enthalphy, symbolized by ΔH, is the amount of heat released (if ΔH<0) or absorbed (if ΔH>0) during a process at constant pressure, for example a chemical reaction.

it means there are 3 atoms of oxygen