1. Table of Contents 8th Grade Science Class
Left side items
Page
Right side items
Table of Contents 1 2 3
Kaleidoscope Analysis 4
Kaleidoscope Lab 5 6
Kaleidoscope Lab Part 2 7
Engineering Design Project Ideas 8
Engineering Design Project
Egg Drop 9
Parts of an Experiment –
Graphic Organizers 10
Part of an Experiment 11
Obscertainer Lab Analysis 12
Intro to Atomic Theory
“Seeing the Un-seeable” 13 14
Atomic Theory Notes 15

2. EQ: Why Do Theories Change Over Time
Questions
How Scientists Learned About the Atom
Pre-assessment: (answer as a complete sentence)
1) Is it easy or hard to study atoms? Why?
It is difficult to study atoms because …
2) What instruments do scientists use to study atoms?
Scientists use _______________ and __________ to study atoms.
3) Draw your idea of what an atom looks like. Label any parts you can.
4) How do you think scientists “see inside” atoms?
5) List any facts you know about the atom.
____________________________________________________
How do we study what we cant see with our own eyes?
Activity 1: Paper Cut
Activity 2: Obscertainer
Trial 1
Trial 2
Actual

3. What was difficult about the obscertainer lab?
What would you do differently if you repeated the lab?
Would you use other materials?
Did you get them all right?

4. What does an atom look like?
How did scientists figure out what it looks like?

5. EQ: Why Do Theories Change Over Time? What Does an Atom Look Like?
Questions
Scientist
Atomic Theory
Picture

6. The atomic model has changed throughout the centuries, starting in 400 BC, when people thought it looked like a ball →
A model uses familiar ideas to explain unfamiliar facts observed in nature.
A model can be changed as new information is collected.

7. Democritus Smallest piece of all matter is not divisible
He named the smallest piece of matter “atomos,” meaning “not to be cut.”

8. Atomos
To Democritus, atoms were small, hard particles that were all made of the same material but were different shapes and sizes.

9. Atomic Theory

10. John Dalton 1760-1844 Father of Modern Atomic Theory
matter is made of atoms
atoms in an element are identical
different elements have different atoms
atoms maintain their mass even in a chemical reaction

11. J.J. Thomson
1897

12. When a magnet was placed near the beam of light, it separated into two parts

13. When a magnet was placed near the beam of light, it separated into two parts

14. Thomson Model
Where did the negative charges come from?
This surprised Thomson, because the atoms of the gas were uncharged.
Where had the negative charges come from?

15. Thomson Model
Proposed a model of the atom that is sometimes called the “Plum Pudding” model.
A small particle
with negatively charged electrons scattered around.

16. J.J. Thomson
1897
discovered electrons (charged particles)