Question

explain the following an element has atoms with different mass number ​

Answer 1

Answer:

Atoms have two numbers associated with them: the atomic number, and the mass number.

The difference between these two numbers is the number of neutrons in the atom.

Most, if not all, elements have a number of isotopes. These are versions of the same element, with (very nearly) the same chemical properties, but with a different number of neutrons.

As an example, hydrogen has three isotopes.

Normal hydrogen, which constitutes the majority of the total, has one proton and no neutrons. It has a mass of 1 AMU.

Deuterium, also known as heavy hydrogen, also has a single proton, but also has one neutron. It has a mass of 2 AMU.

Tritium, an unstable isotope of hydrogen, as a single proton, and two neutrons. It has a mass of 3 AMU.