1a) atomic theory part one
- 2. Learning Intention: By discussion, I will name the three types of particle which form an atom, and describe the structure of an atom.
- 3. Feature of Atom Who by? When?
- 4. Nucleus containing protons and neutrons Electrons orbiting the nucleus Atoms are made from three different particles - protons, neutrons and electrons. For example a lithium atom:
- 5. Particle Position Mass Charge Proton Neutron Electron in nucleus in nucleus orbiting nucleus 1 a.m.u.* 0 a.m.u. 1+ 0 1- *a.m.u. stands for atomic mass unit Complete activity 1.1. 1 a.m.u.*
- 6. Learning Intention: By discussion, I will be able to give a definition for Atomic Number & Mass Number. I will be able to write the nuclide notation of a variety of atoms. I will be able to apply this knowledge to calculate numbers of sub-atomic particles in atoms of various elements.
- 7. Atomic number = number of protons Mass number = number of protons + neutrons Number of neutrons = Mass number – protons In a neutral atom: Number of protons = number of electrons
- 8. Element Atomic Number Mass Number Number of protons Number of neutrons Lithium 3 7 Oxygen 8 8 Sodium 23 11 Sulfur 16 16 Chlorine 17 18 3 4 8 16 11 12 32 16 17 35
- 10. Nuclide notation is a shorthand method to display information about an atom. For example, for a calcium atom: mass number atomic number symbolCa 40 20 Nuclide notation can sometimes be written without the atomic number: 4 He
- 11. • Write the nuclide notation of an atom of sodium with 12 neutrons Na11 23 C6 12 • Write the nuclide notation of an atom of carbon with 6 neutrons
- 12. Nuclide notation can be used to calculate the composition of atoms. Nuclide Notation Atomic Number Mass Number Number of protons Number of neutrons 32 16 39 K19 32 S16 24 Mg12 19 39 19 20 16 16 12 1224 12 Now, try some practice questions – Activity 1.2.
Editor's Notes
- #2: NOTE TO TEACHER – Students copy Black Text. Underlined Words are Keywords for their Glossary Purple Text either instructions or points for discussion.