1. Metric Mania-day 2 September 4 Warm - Up: volume, density Today’s Agenda: 1. collect HW 2. Notes: Volume & Density HW: WS: Finding Volume Reminders: Turn in Safety Contracts 8

2. 9. volume the amount of space an object takes up Draw it:Connect it: displacement method 270 ml - 200 ml = 70 ml

3. 10. density is the mass of the object divided by its volume Draw it:Connect it: sink or float?

4. Volume T. Trimpe 2008 http://sciencespot.net/

5. Metric Units Volume is the amount of space an object takes up. The base unit of volume in the metric system in the liter and is represented by L or l. L kL cL mL

6. Metric Units 1 liter (L) = 1000 milliliters (mL) 1 milliliter (mL) = 1 cm 3 (or cc) = 1 gram* L kL cL mL Which is larger? A. 1 liter or 1500 milliliters B. 200 milliliters or 1.2 liters C. 12 cm 3 or 1.2 milliliters*

7. Measuring Volume We will be using graduated cylinders to find the volume of liquids and other objects. Read the measurement based on the bottom of the meniscus or curve. When using a real cylinder, make sure you are eye-level with the level of the water. What is the volume of water in the cylinder? 43 mL

8. Measuring Volume Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gif Bottom Image: http://morrisonlabs.com/meniscus.htm What causes the meniscus? A concave meniscus occurs when the molecules of the liquid attract those of the container. The glass attracts the water on the sides.

9. Measuring Liquid Volume Images created at http://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf What is the volume of water in each cylinder? Pay attention to the scales for each cylinder. ABC

10. Measuring Volume of a Solid 10 cm 9 cm 8 cm We can measure the volume of regular object using the formula length x width x height. 10 cm x 8 cm x 9 cm = 720 cm 3

11. Measuring Volume of Irregular Object Amount of H 2 O with object = 270 ml - Amount of H 2 O without object = 200 ml Volume of object = 70 ml We can measure the volume of irregular object using water displacement.

12. Density

13. 13 Density Density is the mass per unit volume. A measure of how tightly packed matter is. It is a physical property of a substance. Density = mass / volume Density of water is 1 g/ml or 1 g/cm 3 (memorize this value)

14. 14 Why Objects Float/Sink: ­ NOT because they are "Light", or "Heavy" ­ because they are more dense (sink), or less dense (float) then the liquid they are in. Wood Density: ~ 0.7 g/cm 3 Pure Water Density: 1.0 g/ml Iron Density: ~ 7.9 g/cm 3 Note: ­ Object that is MORE dense than the liquid SINKS ­ Object that is LESS dense than the liquid FLOATS

15. 15 ­ Sinking and floating does not have to do with only wood and iron ­ Liquids sink and float also in other liquids Olive Oil Density: 0.9 g/ml All the delicious things that make up Italian dressing Density: More than 0.9 g/ml, sink to the bottom

16. 16 WS: Finding Volume Volume ball = 100 - 80 = 20 ml