1. Unit 2 – Introduction to matter

2. Monday October 2 nd – Drill Coroner’s Report A coroner is examining the body of a murder victim. He finds some matter that he believes might be important in solving the crime. What are 5 characteristics that the coroner could use to identify this matter?

3. Matter Occupies space Has mass Has inertia

4. Describing Matter - 1 Mass – how much matter in an object.  Basic metric unit is gram

5. Describing Matter - 2 Density – how well matter is packed into the volume that it takes up:  Density = mass ÷ volume  Compare two things that have the same mass. If one takes up more space (has more volume), it is less dense.

6. Describing Matter - 3 Composition – what kind of matter is in an object.  Is it powdered sugar or cocaine?

7. Describing matter - 4 Physical state (solid, liquid, aqueous & gas)  A measure of how much energy matter has. When matter has less energy it is a solid, when it has more energy it is a liquid or even a gas.

8. Describing Matter - 5 Reactivity  To what degree an object will react chemically to its surroundings.  i.e. iron will rust but stainless steel will not.

9. Today: Density Notes Formula for density: D = mass ÷ volume Units (for our labs) are usually grams per milliliter or g/mL Soon we’ll learn how to convert g/mL to kg/L and g/cm 3 * 1 g/mL = 1kg/L = 1 g/cm 3

10. Density Problems – find density What is the density of a dead body that has a mass of 50,000 grams and occupies a volume of 10,000 mL? d = m ÷ v d dead body = 50,000/10,000 = 5 g/mL

11. Density Problems – find mass What is the mass of a dead body that has a density of 5 g/mL and occupies a volume of 8,000 mL? d = m ÷ v therefore m = d x v m dead body = 5 x 8,000 = 40,000 g

12. Density Problems - find volume What is the volume of a dead body that has a density of 5 g/mL and a mass of 90,000 g? d = m ÷ v, therefore v = m ÷ d v dead body = 90,000 ÷ 5 = 18,000 mL

13. Tomorrow Density Lab Let us read it together now. Prepare charts in your lab notebooks. Read lab directions to determine how to set up your charts. You will be graded on their clarity and organization! Remember precision write up is due! Questions?