Atoms, Compounds and Isotopes

Atoms, Compounds and Isotopes

1. Atomic and mass number

   • Mass number = total number of protons and neutrons
   • Atomic number = total number of protons
   • Proton (mass = 1), neutron (mass = 1) and electron (mass = 1/2000)

2. Compounds = chemically bonded

   • Compound = when atoms of two or more elements chemically combine

3. Isotopes

   • Isotopes = different atomic forms of the same element which have the same number of protons but different number of neutrons
   • Carbon-12 and Carbon-14
     • Carbon-12 has 6 protons, 6 neutrons and 6 electrons
     • Carbon-14 has 6 protons, 8 neutrons and 6 electrons