1. Chapter 6: An Introduction to Atoms

2. Atomic Theory Development Key Players – Democritus – Dalton – Thomson – Rutherford – Bohr

3. the atom Literally means… – Not able to be divided It is the smallest item that an element can be divided and still be the same element.

4. the atom How small is an atom?

5. JJ Thomson Plum Pudding Model – Aka Chocolate Chip Ice Cream Model

6. Ernst Rutherford at the center of an atom – Nucleus

7. Subatomic particles Protons – Positive charge Neutron – Neutral charge Electron – Negative charge

8. the atom

9. Subatomic particles Location – Nucleus Protons & neutron – Electron Cloud Electron Mass – Only protons and neutrons are measurable – Electrons way too small to measure

10. Isotopes Protons stay the same but… – Neutrons either increase or decrease – Changes the atomic mass

11. isotopes What is this element? Silver What is the atomic mass of this isotope? 108

12. atomic measurement Atomic Mass Unit Atomic Mass Mass Number

13. atomic measurement Atomic Mass Unit – Unit that describes the mass of an atom Atomic Mass – Weighted average mass of all natural isotopes of an elements Mass Number – Sum of the protons and neutrons

14. Mass number Mass Number…… 13 # of Protons……… - 6 _____________________ # of Neutrons….. 7

15. Terms to Know Atom Electrons Electron Cloud Isotopes Protons