Question

Which of these properties is the best one to use for identification of an element? 1.the number of neutrons in the atomic nucleus
2. the number of protons in the atomic nucleus
3.the number of isotopes that are formed by the element
4. the number of charges on ions of the elemen

Answer 1

The right answer is 2.

The number of protons contained in a nucleus (called an atomic number) is characteristic of a chemical element. For a given atomic number, the number of neutrons defines different "types" of this element: isotopes. The variation of the number of protons of the nucleus of an atom, during a nuclear reaction for example, causes a change of the element studied.

Answer 2

Answer: Option (2) is the correct answer.

Explanation:

Atomic number of an atom means the total number of protons and atom contains. Each atom or element has different number of protons.

For example, atomic number of nitrogen is 7 whereas atomic number of sodium is 11.  

This also means that in a nitrogen atom there are 7 protons and in a sodium atom there are 11 protons.

Thus, we can conclude that the property number of protons in the atomic nucleus is the best one to use for identification of an element.