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← 1.1 Structure of the atom

Metals: few outer electrons

Integrated Science · Grade 9 · about 40 minutes

Among the first 20, metals have 1, 2 or 3 outer electrons. Use Na, Mg, Al, K and Ca. Skip iron: Z=26 is outside the first 20. Aluminium sufurias; sodium in salt.

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Other lessons in this sub-strand

  1. Atom, element and particle
  2. The proton: positive, in the nucleus
  3. The neutron: no charge, in the nucleus
  4. The electron: negative, on shells
  5. The nucleus is protons plus neutrons
  6. Atomic number Z is the number of protons
  7. Mass number A is protons plus neutrons
  8. In a neutral atom, electrons equal protons
  9. Energy levels fill 2, then 8, then 8, then 2
  10. Arrangements of carbon, oxygen, sodium and chlorine
  11. Dot diagrams: nucleus, rings, then dots
  12. Metals: few outer electrons
  13. Non-metals: more outer electrons, or a full shell
  14. Practise the first 20: hydrogen to calcium