Isotopes have the same number of: 

Concept:

Each element is distinguished by the number of protons, neutrons and electrons that it possesses. Atoms with the same number of protons but different numbers of neutrons are called isotopes. They share almost the same chemical properties, but differ in mass and therefore in physical properties.

The isotopes of a chemical element are a group of atoms that have the same atomic numbers but different mass numbers. This implies that all isotopes of an element have the same number of protons in their atomic nuclei and the same number of electrons in the electron cloud surrounding the nucleus. However, they differ in the total number of neutrons present in their respective atomic nuclei.

For example

1. Carbon-14, Carbon-13, and Carbon-12 are all isotopes of carbon. Carbon-14 contains a total of 8 neutrons, carbon-13 contains a total of 7 neutrons, and carbon-12 contains a total of 6 neutrons.

2. Uranium-235 and Uranium-239 are two different isotopes of the element uranium.

3. The three isotopes of hydrogen are as:

• Protium, or Hydrogen-1. This isotope of hydrogen contains 1 proton, 1 electron, and no neutrons- \(H_1^1\)

• Deuterium, or Hydrogen-2. This isotope of hydrogen contains 1 proton, 1 electron, and 1 neutron-\(H_1^2\)

• Tritium, or Hydrogen-3. This isotope of hydrogen contains 1 proton, 1 electron, and 2 neutrons-\(H_1^3\)

Hence, the correct answer is Option-1-protons.