How do isotopes of an element differ?

1 Answer
May 16, 2018

Answer:

By the number of NEUTRALLY-CHARGED nucular particles....i.e. by the number of #"neutrons.."#

Explanation:

An atom is characterized as a particular element by the number of positively-charged, MASSIVE nuclear particles, i.e. #Z#...

#Z=1#, we gots hydrogen, #Z=2# we gots helium, #Z=3#, lithium......#Z=47# we gots silver....

The nucleus can also contain neutrons, massive nuclear particles of ZERO charge. Together with protons, these particles engage in the strong nuclear force, the which, at impossibly short nuclear ranges, is STRONGER than the electrostatic force of repulsion, and binds nuclei together.

The atomic mass printed on the Periodic Table is the weighted average of the different mass numbers... Hydrogen, for which #Z=1# of course, has a few accessible isotopes, i.e. #""^2H#, and #""^3H#, and these are routinely used by chemists in labelling studies. The atomic mass of heavier elements, tends to be the mass envelope of different isotopes...