Question

What part of the atom determines the identity of an atom?

Answer 1

Answer:

The number of protons in the nucleus of an atom is its atomic number (Z). This is the defining trait of an element: Its value determines the identity of the atom. For example, any atom that contains six protons is the element carbon and has the atomic number 6, regardless of how many neutrons or electrons it may have .

Answer 2

Every element has a unique atomic number. The atomic number is equal to the number of protons within the nucleus of every atom of the element. There are actually no two elements with the same number of protons within their atoms, so this numbers helps to identify an element.

In summary, the one thing that can determine an atom's identity would be the number of protons.

Hope this helps!