Which particle is most likely present in the nucleus of the atom

Explanation:

An atom consists of three subatomic particles. These are protons, electrons and neutrons.

A proton has a positive charge, an electron has a negative charge and a neutron has no charge.

A nucleus is the central part of an atom. And, inside the nucleus there are protons and neutrons. Whereas electrons move in circular path outside the nucleus.

Hence, we can conclude that most likely protons and neutrons are present in the nucleus of the atom.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.