1. How are the protons and electrons in atoms arranged?
Super Models
How are the protons and electrons in atoms arranged?

2. In your notebook Super Model, Part 2 Modeling atoms using math
Rutherford’s model
In your notebook

3. Reading, p. 172 Let’s go over the reading together Mathematical models
How many dates per year your have
How many cars per lifetime you crash
Etc.
Reading, p. 172

4. Scientific Notation A short-hand way of writing large numbers without
writing all of the zeros.

5. The Distance From the Sun to the Earth
93,000,000

6. Step 1 93,000,000 = 9.3000000 Move decimal left
Leave only one number in front of decimal
93,000,000 =

7. Step 2
Write number without zeros
93,000,000 = 9.3

8. Step 3 7 93,000,000 = 9.3 x 10 Count how many places you moved decimal
Make that your power of ten
93,000,000 = 9.3 x 10 7

9. The power of ten is 7 because the decimal moved 7 places. 7
93,000,000 = 9.3 x 10 7

10. 93,000, Standard Form
9.3 x Scientific Notation

11. Practice Problem -----> -----> -----> ----->
Write in scientific notation.
Decide the power of ten.
98,500,000 = 9.85 x 10?
64,100,000,000 = 6.41 x 10?
279,000,000 = 2.79 x 10?
4,200,000 = 4.2 x 10?
9.85 x 107
----->
6.41 x 1010
----->
2.79 x 108
----->
----->
4.2 x 106

12. More Practice Problems
On these, decide where the decimal will be moved.
734,000,000 = ______ x 108
870,000,000,000 = ______x 1011
90,000,000,000 = _____ x 1010
Answers
3) 9 x 1010
7.34 x 108
2) 8.7 x 1011

13. Complete Practice Problems
Write in scientific notation.
50,000
7,200,000
802,000,000,000
Answers
1) 5 x 104
2) 7.2 x 106
3) 8.02 x 1011

14. Scientific Notation to Standard Form
Move the decimal to the right
3.4 x 105 in scientific notation
move the decimal
--->
340,000 in standard form

15. Move the decimal to the right.
Write in Standard Form
Move the decimal to the right.
6.27 x 106
9.01 x 104
6,270,000
90,100

16. Worksheet
Get ‘r’ dun!
Super important skill for science

17. P&P p. 173 2. Modeling something in your life: Some translations:
Think of a situation where math models help you plan
Describe it in a sentence
Translate the sentence into a model
Some translations:
“Makes” - “=“
“And” – “+” or “x”
“Between all of us” or “Shared” - “/”
P&P p. 173

18. P&P 173 3. Math time! D = Speed X Time
A. Here’s the answer: 1.3 X 103m
How did we get that?
D = Speed X Time
D = (3.0 X 107 m/s) X (4.2 X 10-5 s)
D = m/s X s
D = 1300 m
P&P 173

19. 3. Continued:
B. Do you think Rutherford made his lab that long? Why or why not?
P&P 173

20. P&P 173 3. Continued Distance is Speed X Time Time = Distance/Speed
C. Rutherford’s lab was 10 meters long (not the 1300 we talked about earlier). How long would it take for the alpha particles to move that distance?
Distance is Speed X Time
Time = Distance/Speed
Speed = 3.0 X 107 m/s
Distance = 10 meters
P&P 173

21. P&P 178 3. Continued… D. How fast did the particle travel?
(Speed = Distance/Time)
50 X 10-9 m
1 X seconds
P&P 178

22. P&P 178-179, Question 4 Goal: make a properly scaled model of an atom
What would the volume of a model atom be if you have a nucleus the size of a grapefruit?
Very difficult, but you need to take your time and do it
Volume of grapefruit:
P&P , Question 4

23. A: just giving you the diameter of an atom and a nucleus
A: just giving you the diameter of an atom and a nucleus. You will need this.
B, C: giving you formulas you will need
D: the table you will use to figure out the volume of the model atom.
E: Think about how…
Ratio of volume of nucleus to the volume of atom is the same as volume of grapefruit to volume of the whole model
Notice they give DIAMETER of atoms and nuclei when you need RADIUS; how are those related?
Question 4

24. Is it ultimately possible for us to make a good model using a grapefruit?
How far would we have to put the edge of the atom away from the nucleus (how big is the radius)?
Does this mathematical model help you understand it all?
Question 4