Key Definitions - Unit 1

Key Definitions - Unit 1

1. Isotope - atoms of the same element with different number of neutrons and different mass number

2. Atomic number (proton number) - the number of protons in the nucleus of an atom

3. Mass (nucleon) number - number of protons and neutrons in the nucleus

4. Ion - a charged atom or (covalently bonded) group of atoms ( molecular ion)

5. Relative Isotopic Mass - mass of an atom of an isotope compared with 1/12 of the mass of carbon-12

6. Relative Atomic Mass - weighted mean mass of an atom of an element compared with 1/12th of the mass of C-12.

7. Relative Formula Mass - weighted mean mass of a formal unit compared with 1/12th of the madd of an aim of C-12

8. Relative MolecularM Mass, weighted mean of a molecule compared with 1/12 of a C-12 atom