1. Physical/Chemical Properties and Changes

2. Physical properties - Conditions that can be seen without changing the substance’s make-up (composition)

4. Chemical property – the ability of a substance to undergo a change that will transform it into a completely new substance
Will the substance react or not?

5. Physical Change – a change in properties that do not alter the make-up
May change appearance
Physical changes involve gaining or releasing energy

7. Chemical change: when one or more substances change into entirely new substances with different properties
Energy either taken in or given off

8. Physical The composition does not change Matter stays the same!
Chemical The composition of the matter always changes = Chemical reaction! REACTANTS TURN INTO PRODUCTS!
VS.
Physical The composition does not change Matter stays the same!

9. Indicators of Chemical Changes
1. A solid precipitate forms from mixing solutions

10. Indicators of Chemical Changes
2. Heat or light is produced or consumed

11. Indicators of Chemical Changes
3. Gas is produced

12. Indicators of Chemical Changes
4. Color change

13. Density – A Physical Property
Density – ratio of the mass of an object to its volume

14. Density
Density can be used to identify a substance

15. Density Triangle Density can be used to find mass or volume…
Units: g/mL or g/cm **1 mL = 1 cm3

16. Density Calculations
A piece of plastic has a mass of 1.55 g and has a volume of 1.3 cm3. What is the density of this plastic?

17. Water Displacement
water displacement is used to measure the volume of an irregular solid

18. Water Displacement
PROBLEM: A medallion has a mass of g. A graduated cylinder is filled to a volume of mL and when the medallion is placed in the cylinder, the water volume rises to 77.8 mL. What is the density and is this medallion platinum (d = 21.4 g/cm3) or silver (d = g/cm3)?

19. Using Density in Calculations
PROBLEM: Mercury has a density of 13.6 g/mL. What volume of mercury must be taken to obtain 225 g of the metal?   

20. Using Density in Calculations
PROBLEM: Magnesium’s density is 1.74 g/cm3. What mass of magnesium would have a volume of cm3? 

21. Density Graphs Mass vs. volume graphs Should be straight line!
Slope of line = density
Slope = rise/run