1. The Chemistry of Life Section 2.1: The Nature of Matter Teacher: Mrs. Rolle Presenter: Mevan Siriwardane September 27, 2007

2. Atomic Structure

3. ELECTRON – negative, mass nearly nothing PROTON – positive, same mass as neutron (“1”) NEUTRON – neutral, same mass as proton (“1”)

4. The Atom Nucleus Electron Shell or Orbit

5. The Atom Hydrogen Proton Electron Hydrogen has one proton, one electron and NO neutrons

6. The Atom Helium Electron Proton Neutron Helium has two electrons, two protons and two neutrons

7. Mass and atomic number Particle Relative Mass Relative Charge Proton11 Neutron10 Electron0 MASS NUMBER = number of protons + number of neutrons SYMBOL PROTON NUMBER = number of protons (obviously)

8. The Atom Helium Electron Proton Neutron Helium has two electrons, two protons and two neutrons

9. The Atom Lithium Protons Neutrons Electrons

10. The Atom Beryllium Protons Neutrons Electrons Beryllium has four electrons, four protons and five neutrons.

11. The Atom Boron Protons Neutrons Electrons Boron has five electrons, five protons and six neutrons.

12. The Atom Carbon Protons Neutrons Electrons Carbon has six electrons, six protons and six neutrons.

13. The Atom Nitrogen Protons Neutrons Electrons Nitrogen has seven electrons, seven protons and seven neutrons.

14. The Atom Oxygen Protons Neutrons Electrons Oxygen has eight electrons, eight protons and eight neutrons.

15. The Atom Fluorine Protons Neutrons Electrons Fluorine has nine electrons, nine protons and ten neutrons.

16. The Atom Neon Protons Neutrons Electrons Neon has ten electrons, ten protons and ten neutrons.