isotopes and RAM

• isotopes are different forms of the same element, which have the same no. of protons but a different no. of neutrons.
• isotopes have the same atomic no. but different mass no.
• the bigger number in the periodic table is the relative atomic mass
• the relative atomic mass of an element is the average mass of one atom compared to 1/12th of the mass of one atom of carbon-12
• if an element only has one isotope its relative atomic mass will be the same as its mass number
• relative atomic mass = isotope abundance x isotope mass number / sum of abundances of all the isotopes