GENERAL KNOWLEDGE

Detailed explanation-1: -Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. The number of protons in a nucleus determines the element’s atomic number on the Periodic Table.

Detailed explanation-2: -Isotopes are each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties.

Detailed explanation-3: -Isotopes. An isotope is one of two or more forms of the same chemical element. Different isotopes of an element have the same number of protons in the nucleus, giving them the same atomic number, but a different number of neutrons giving each elemental isotope a different atomic weight.

Detailed explanation-4: -Atoms of the same element that contain the same number of protons, but different numbers of neutrons, are known as isotopes. Isotopes of any given element all contain the same number of protons, so they have the same atomic number (for example, the atomic number of helium is always 2).

Detailed explanation-5: -The correct answer is (a) elements have isotopes. Elements are defined by the number of protons in the nucleus of an atom. However, there can be variation in the number of neutrons in the nucleus of atoms of the same element.