All isotopes of an element have the same number of neutrons. have the same number of protons. have the same atomic number. have the same mass number. have different chemical properties.

ALL ISOTOPES OF AN ELEMENT HAVE THE SAME NUMBER OF;

1. PROTON

2. ATOMIC NUMBER

Explanation:

Isotopes are atoms with the same atomic number but different mass numbers. Isotopes of an element has the same number of proton which dictates the atomic number of the atoms. The difference in mass number is as a result of the difference in the number of neutrons. Isotopes of an atom have different physical properties but they exhibits the same chemical properties because neutrons have no influence on the chemical properties and the change or difference in neutrons will produce no effect on the chemical properties of the atoms. Neutrons only contributes to the mass of the atoms giving the isotopes of an atom different mass numbers. An example is chlorine with two isotopes, Cl -35 and Cl -37.

Properties                            Cl-35                                                    Cl-37

mass number                        35                                                        37

atomic number                      17                                                         17

number of protons                17                                                          17

number of electrons                17                                                       17

number of neutrons        35-17 = 18                                             37-17 = 20

abundance in nature             75%                                                    25%