2. Length is a measure of distance. Scientists use the Metric System: How much? 2.4 cm or 24 mm U1C3A1 Measurements

3. Volume is the measurement of the amount of space an object occupies. Scientists measure it in cm 3. To calculate the volume of a regular solid multiply the length by the width by the height Volume= length x width x height U1C3A2 Volume of regular solids 3cm x 4cm x 2 cm= 24 cm 3

4. U1C3A3 Volume of Liquids A Graduated Cylinder is a tall thin tube measured off in units. A graduated cylinder is used to measure volume of liquids. Volume of liquid? 43.0 mL

5. U1C3A4 Measuring Mass Mass is the amount of matter that a body contains. It is measured in grams. Mass is different than volume (volume is the amount of space something takes up.) Mass is also different from weight (weight is how hard gravity pulls on something) Gases have mass. The mass of the ball is more after more air has been pumped into it.

6. Using a Triple Beam Balance to find Mass Balance the scale with weights locked in and pointing directly at a number. Add up all the numbers to get the mass. ____ + ___ + ___ = _____ 300 + 70 + 3.35 = 373.35 g

7. Density U1C3A5 We know that the amount of mass in a cube of the same size is not always the same. Why is that? It depends on what it is made of. The reason is density Density is a comparison of how much matter there is in a certain amount of space.

8. Which one is more dense? How about this: Which square is more dense?

9. Which one is more dense? How about this: Which square is more dense? There is more stuff in the same volume of space.

10. Which one is more dense? Now which one is more dense?

11. Which one is more dense? Now which one is more dense? There is the same amount of “stuff” but in a smaller amount (volume) of space

12. What is density? (Put in your notes) Mathematical Definition Density = mass OR mass ÷ volume. volume Units for density: g. cm 3 ALWAYS REMEMBER UNITS!

13. Density= Mass divided by Volume I Density Density Mathematical Definition

14. Let’s try a density problem together Frank has a paper clip. It has a mass of 9g and a volume of 3cm 3. What is its density? 9g  3cm 3 = 3 g/cm 3 Frank also has an eraser. It has a mass of 3g, and a volume of 1cm 3. What is its density? 3g  1cm 3 = 3 g/cm 3

15. Density, Mass, Volume Formulas Make the density triangle (use I love density to help you). Cover up the variable you are solving for. Look at the equation to use.

16. Liquid Layers If you pour together liquids that don’t mix and have different densities, they will form liquid layers. The liquid with the highest density will be on the bottom. The liquid with the lowest density will be on the top.

17. Liquid Layers Check out this picture from your book. Which layer has the highest density? Which layer has the lowest density? green Imagine that the liquids have the following densities: –10g/cm 3.green3g/cm 3. yellow –6g/cm 3.red5g/cm 3. blue

18. Liquid Layers Which liquid has the highest density? Golden syrup Which liquid has the lowest density? oil Which liquid has the middle density? water

19. Imagine that the liquids on the right have the following densities: –15g/cm 3 10g/cm 3 –3g/cm 3 9g/cm 3 –7g/cm 3 12g/cm 3 3g/cm 3 7g/cm 3 9g/cm 3 10g/cm 3 12g/cm 3 15g/cm 3 Liquid Layers – Try on your own!

20. Super Scientist Question of the Day Jake has a book, a ruler, and a balance. How can Jake find the density of the book with the tools he has?

21. Density of Irregular solid Water Displacement Method 1.Measure volume of liquid in graduated cylinder (starting level) 2.Carefully place the object into the graduated cylinder 3.Measure the volume of liquid with object in it (final level) 4.Final level – Starting level = volume of object Example Start level=50 Final level=80 Volume of object= 80 mL-50mL=30mL D=M=174g=5.8g/mL V 30mL

22. Density of Liquids 1.Find the volume of the liquid 2.Find the mass of the liquid and the container 3.Find the mass of the empty container 4.Subtract the Mass of liquid and container from mass of empty container Example Volume= Mass container & liquid 95.9g D=M=71g=1.05g/mL V 68mL 68 mL Mass container only 24.5g Mass of liquid only= mass both-container only= 71.4 g

23. U1C3A6 Electrical Conductivity Electrical conductivity measures how easily electricity travels through a substance. It is another characteristic property (like density) that can be used to identify an unknown substance. In the lab, you found that copper wire was a much better conductor (it has a higher electrical conductivity) than the nichrome wire. The light bulb was brighter with the copper wire.

24. Density is a characteristic property. A characteristic property is a measurement (in numbers) that is different for different types of materials. You can use a characteristic property to identify (or help identify) a substance. Characteristic Properties Density Electrical conductivity Boiling point Melting point U1C3A6 Density continued Non-Characteristic Properties Mass Volume Temperature