1. What does Density measure?
Density: Measure of how compact (close) the molecules of a substance are.

2. Density Equation
Density is a measure of the objects mass in a particular volume.
Density = Mass D = M
Volume V

3. Example mass = 200 g D = m Volume = 25 mL V Density = ? D = 200 g
D = 8 g/ml

4. Density Triangle 1. Cover what you are looking for with your finger.M D
1. Cover what you are looking for with your finger.
2. The remaining letters tell you what mathematical function to perform. M
D V
M =
V = DV

5. If I cut a block of wood in half what happens to the density of the wood?

6. Stays the Same!
Why?
Cutting it in half does not change the arrangement of the molecules inside.

7. IMPORTANT!
The density of a substance will stay the same regardless of the size of the sample!
We can identify the substance by its density.

8. Density Table Material Acrylic Aluminum Brass Copper Oak Pine
Polypropylene
PVC
Steel
g/cm3
2.70
8.96
7.9

9. Comparing Density
We can estimate the density of an object by comparing it to another object with a known density.

10. WATER Density of Water = 1 g/ml
If an object floats what can you say about its density?
If an object sinks what can you say about its density?

11. Density is < 1 g/ml Density = 1 g/ml Density is > 1 g/ml

12. Eyepiece (10X) Body tube arm aperture Stage clips stage
nosepiece
arm
Medium power
Objective lens
aperture
high power
Objective lens
Stage clips
Course adjustment
stage
Fine adjustment
Light
diaphragm
Base

13. Rules for Microscope 1. Turn on the ___________.
2. Always begin with the _______________.
3. Focus with __________________.
4. Center the object before turning to __________________.
5. Never use the ______________ with the high power objective lens.
Low power objective lens
light
Course adjustment knob
High power
Course adjustment

14. 100x
Center the object
scan with low power

15. 400x
Then Zoom In

16. What is “Field of View”?
Measurement of the area that can be seen

17. Is the field of view larger or smaller under high power?
Explain.

18. How do we know how wide the field of view is?
We have to measure it while looking through the microscope.
4mm
4mm

20. 2 mm

21. How many boxes wide is the field of view?
3.5mm

22. How did you figure out the size of the objects?
4mm
1mm

23. 4mm 1mm How big is the Paramecium?
When you place the grid on the stage and look at it under 40x, this is what you see.
When you look at a paramecium under 40 x, this is what you see
How big is the Paramecium?
1mm

24. The protist is about
2.5 mm.
5mm

25. One Volvox = about one third of the FOV
1.6 mm
Low Power FOV = 1.6 mm
One Volvox = about one third of the FOV
= 0.53 mm

26. Paramecium
0.4 mm
High Power FOV
= 0.4mm
Paramecium= 0.2mm

27. Amoeba
0.4 mm
High Power FOV= 0.4 mm
Amoeba = about 0.3 mm

28. Number that can fit across
Size of Object
Size of object =
Field of View
Number that can fit across

29. 9mm

30. Field of view
Number that can fit
3mm
3mm
3mm
9mm 3
= 3mm
9mm

31. Field of view
Number that can fit
3mm 5
0.6 mm
3mm

32. DO NOW:
How wide is the Amoeba?
1 mm

33. How wide is the euglena?
2 mm 4
0.5 mm

34. 4mm 1mm How big is the Paramecium?
When you place the grid on the stage and look at it under 40x, this is what you see.
When you look at a paramecium under 40 x, this is what you see
How big is the Paramecium?
1mm