Atoms and Elements

Atoms and Elements

1. Atoms

   • Nucleus
     • Protons
       • Positively charged
     • Neutrons
       • No charge (neutral)
     • In the middle of the atom
   • Electrons
     • Negative charge
     • Orbit nucleus
     • Occupy shells

2. Elements

   • Substance that contains ONLY one type of atom
   • Different element different number of protons

3. Periodic Table

   • Top number(largest number) is the mass number
     • Number of protons and neutrons added together
   • Bottom number(smallest number) is the atomic mass
     • Number of Protons
       • Also number of electrons as the proton number and electron number are EQUAL
   • To find number of neutrons
     • Subtract atomic number from mass number