1. 3.1 What is the history of the atom?
Unit 3 ATOMIC CONCEPTS
3.1 What is the history of the atom?
AIM: What is an atom and who are Dalton, Thomson and
Rutherford?
DO NOW:
Both of the pictures are results related to the structure of the atom. Make some observations. What are some similarities and differences? What kind of conclusions can you draw about the atom? WRITE IT DOWN

2. VOCABULARY Electron Atomic number Atom Atomic mass Orbital
Gold Foil Experiment
Wave-Mechanical Model
Subatomic particles
Proton
Neutron
Electron
Atomic number
Atomic mass
Electron configuration
Average atomic mass
Isotope
Valence electron
Lewis dot diagram
Ground state
Excited state
Periodic Table
Charge

3. The basic unit of matter
WHAT IS AN ATOM?
A tiny particle
The basic unit of matter

4. STATIONS 1. Conduct the reading at each station.
2. Answer the questions in your notes using the reading.
3. Fill your GRAPHIC ORGANIZER as you complete the stations.
STATION 1
STATION 1
STATION 2
STATION 2
STATION 3
STATION 3

5. INDEPENDENT PRACTICE worksheet
NEXT
Complete the
INDEPENDENT PRACTICE worksheet
When you are done, you may work on the following:
CHEMISTRY VOCABULARY JOURNAL
- you will be allowed to use this on your quizzes and (some of) your exams

6. STATION 1 JOHN DALTON (1803) All matter is made of atoms
Atoms are indivisible
Atoms are indestructible
All atoms of an element are identical
Compounds are formed with two or more kinds of atoms
Chemical reaction is a rearrangement of atoms.

7. STATION 2 J.J. Thomson (1897)
Experimentally discovered that atoms have NEGATIVE CHARGES
Discovered the ELECTRON

8. STATION 3 Rutherford’s Gold Foil Experiment (1911)
QUESTION: If the plum-pudding model is composed of positive and negative charges dispersed uniformly (“spread evenly”) in a sphere, then what do you predict will happen if you shoot positive particles at it?

9. STATION 3 Rutherford’s Gold Foil Experiment (1911)
RESULTS OF THE EXPERIMENT:
Atoms are mostly empty space
Atom has a DENSE, POSITIVELY CHARGED NUCLEUS surrounded by electrons