How do isotopes of a given element differ?

Because the atomic mass of argon on the periodic table is 39.948, that is closest to Ar-40, so that isotope must have the highest percentage of all three of the isotopes. List the protons, neutrons and electrons in each isotope, Li-6 and Li-7. read more

Isotopes of an element will contain the same number of protons and electrons but will differ in the number of neutrons they contain. In other words, isotopes have the same atomic number because they are the same element but have a different atomic mass because they contain a different number of neutrons. read more