Which of the following describes an isotope? 1. atoms of an element that have the same number of protons but a different number of electrons

2. atoms of an element that have the same number of protons and a different number of neutrons

3. atoms of an element that have the same number of protons and the same number of neutrons

4. atoms of an element that have the same number of electrons and the same number of neutrons

2. atoms of an element that have the same number of protons and a different number of neutrons

Explanation:

Isotopes of an element is made up of atoms of an element that have the same number of protons and a different number of neutrons.

The number of protons are the positively charged particles in an atom

The number of neutrons are the uncharged particles.

Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their carious nuclei.

Isotopes have have the same electronic configuration and hence will have similar chemical properties. They only differ in their masses.

a and b sometimes have a positive value