Isotopes of the same element have different? ?

numbers of neutrons

Explanation: Isotopes are different versions of a particular element or different versions of a certain kind of atom.

Protons and electrons determine an atomic element's chemical characteristics. The neutrons are a different matter. They have no charge, but do have almost the same mass as a proton. Different isotopes of an atomic element contain different numbers of neutrons.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.