could some one explain mass number and what they look like for different isotopes?

Question

could some one explain mass number and what they look like for different isotopes

Answer 1

Mass number can be approximated as the sum of the number of protons and the number of neutrons, with each of those given a weigth of 1 gram. For isotopes the number will either be more or less then 2 x the atomic number as you have more or less neutrons

Answer 2

Mass number is the sum of protons and neutrons in the nucleus. Carbon atoms all have 6 protons in the nucleus. Common isotopes of C are C-12 (6 neutrons), C-13 (7 neutrons), and C-14 (8 neutrons).

Answer 3

Mass number = #of protons + # of neutrons in an atom. Elements can have more than 1 isotope, which are atoms of the same element with different numbers of neutrons. Since the number of protons is the same for atoms of the same element, the atomic number will be the same for these isotopes, but the mass numbers will be different.

Answer 4

the mass number is the total mass of an atom (the protons and neutrons; electrons are so tiny they don't count). the mass number you see on the periodic table is the average mass of all the isotopes. the mass number for individual isotopes is given as a superscript after the atom's abbreviation, for example, carbon can exist as C^12 and C^13.