How does an atom of one element differ from the atom of another element? -Are there other ways to change the identity of an atoms? Explain, please.

Explanation:

The atoms of one element differs from the atoms of other elements in terms of the number of protons they contain. This is often taken as the atomic number of such an atom.

II.

It is possible to change the identity of an atom. This is only possible by altering the atomic number of the atom.

Only nuclear reactions have this capability.

When an atom undergoes nuclear reaction that involves change in number of protons, transmutation occurs and a new atom forms.

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