Atoms

• The size of an atom is 1x10^-10 m.
• The radius of the nucleus of an atom is 0.1 nanometers or 1 x 10^-14m.
• Atoms have no overall charge
• What is the relative mass of an electron?

  Very small
• An atom is made of electrons, protons and nuetrons,
• Electrons orbit the atom's nucleus in shells.
• The 'boxes' in the periodic table are nuclear symbols that represent atoms
• Label the diagram

  A) mass number

  B) atomic number

  C) elemental symbol

  
• What does the atomic number tell you?

  How many protons there are
• What does the mass number tell you?

  Total number of neutrons and protons
• Protons determine what element an atom is.