1. Atoms and Molecules Unit 4A The Building Blocks of Matter

2. All matter is formed by: Atoms Molecules Molecules are groups of different types of atoms bonded together.

3. Subatomic Particles (Parts of an Atom) Proton Electron Neutron Measured by AMU’s Atomic Mass Unit

4. Parts of an Atom ParticleLocationChargeMass P+P+ Nucleus + 1 amu e-e- Outside - 0 amu N0N0 Nucleus 0 1 amu

5. Parts of an Atom Atoms are mostly empty space. Ex: If you put a golf ball in the middle of a football stadium (nucleus), the electrons would be WAY up in the nosebleed sections.

6. Atomic Models The current model is Electron Cloud, but it is complicated. So… We will be using the Bohr Model.

7. The Bohr Model Electrons surround the nucleus in different energy levels. e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- P + N 0

8. Elements Elements = only 1 kind of atom The # of PROTONS in that element tell us which element it is Listed on P.T. as atomic number

9. The Atomic Number tells us the number of Protons an atom has It also tells us how many electrons a neutral atom has REMEMBER - APE

10. Isotopes Isotopes – elements that have the same # of protons and a different # of neutrons Isotopes have different masses.

11. Atomic Mass Mass number = the mass of one atom Atomic mass = the average mass of all isotopes of that element. Mass # = #P + + #N 0

12. Isotope Notation C 12 6 C 6 13 C 14 6 Mass # Atomic #