1. Which do you think would have the greater mass and greater volume? Why?
1 kg of rock
1 kg of feathers

2. Matter is any substance which: Has mass
Anything that doesn't matter has no mass.
Matter is any substance which:
Has mass
Occupies space (i.e. has volume)

3. Volume – amount of space an object takes up
Indirectly
Volume – amount of space an object takes up

4. Mass is the amount of Matter in an object
Weight is the gravitational force acting on an object
Grams (g)
Kilograms (kg)
1 kg = 1000 g, kilo means thousand
0.001 kg = 1 g
To convert grams to kilograms, divide the number of grams by 1000
To convert kilograms to grams, multiply the number of kilograms by 1000

5. If each circle weighs equally and each square has the same volume……
Which square is more dense?

6. Which one is more dense?

7. To find the density 1- Find the mass of the object
2- Find the volume of the object
3- Divide
Density = Mass_
Volume

8. Density of Different Substances
distilled water has a density of 1.00 g/mL, which means that every mL of distilled water has a mass of 1.00 g
birch wood has a density of 0.66 g/cm3 (in other words 0.66 g/mL) which means that every cubic cm of birch wood has a mass of 0.66 g

9. Density: Float or Sink?
if the density of object A is less than that of object B, then A will float on top of B
eg. birch wood will float when placed in water since its density (0.66 g/cm3) is less than that of water (1.00 g/mL)
if the density of object A is more than that of object B, then A will sink in B
eg. a piece of iron will sink in water since its density (7.87 g/cm3) is more than that of water (1.00 g/mL)

10. A Density Problem…
eg. if water (D = 1.00 g/mL), rubbing alcohol (D = g/mL) and vegetable oil (D = 0.92 g/mL) were all placed in a container, what would you expect to occur? Why?
The rubbing alcohol would form a top layer since it’s the least dense and would therefore float on top of the other substances. The vegetable oil would form a middle layer since it would sink below the alcohol but float on the water. The water would form a bottom layer since it has the highest density so would sink in the other substances.

11. DENSITY Density is just the amount of matter within a certain volume.
Density is the amount of matter within a certain volume.

12. D = 𝑀 𝑉 = 35 𝑔 7 𝑚𝐿 = 5 𝑔 𝑚𝐿 To find density:
Find the mass of the object
Find the volume of the object
Mass Divided by Volume
Ex. If the mass of a liquid is 35 grams and it takes up 7 mL of space, calculate the density.
D = 𝑀 𝑉
= 35 𝑔 7 𝑚𝐿
= 5 𝑔 𝑚𝐿
Liquids and Gases have the density units: g/mL

13. D = 𝑀 𝑉 = 45 𝑔 9 𝑐𝑚3 = 5 𝑔 𝑐𝑚3 To find density:
Find the mass of the object
Find the volume of the object
Mass Divided by Volume
Ex. If the mass of an object 45 grams and its volume is 9 cm3, calculate the density.
D = 𝑀 𝑉
= 45 𝑔 9 𝑐𝑚3
= 5 𝑔 𝑐𝑚3
Solids have the density units: g/cm3

14. V = 𝑀 𝐷 = 60 𝑔 10 𝑔/𝑐𝑚3 =6 𝑐𝑚3 To find volume from density:
Ex. If the mass of an object 60 grams and its density is 10 g/cm3, calculate the volume.
V = 𝑀 𝐷
= 60 𝑔 10 𝑔/𝑐𝑚3
=6 𝑐𝑚3

15. M =D x V = 5 𝑔 𝑚𝐿 x 4 mL = 20 g To find volume from density:
Ex. If the volume of an object 4 mL and its density is 5 g/mL, calculate the mass.
M =D x V
= 5 𝑔 𝑚𝐿 x 4 mL
= 20 g

16. Sample Density Calculations
A liquid has a mass of 150 g. If its density if 0.95 g/mL, find the volume of the liquid.
V = 𝑀 𝐷
= 150 𝑔 0.95 𝑔/𝑚𝐿
= mL

17. Sample Density Calculations
A block of fir measures 10 cm by 8 cm by 3 cm. If its mass is 144 g, find the density of the wood.
Find volume first…..
V = L x W x H
= 10 cm x 8 cm x 3 cm = 240 cm3
D = 𝑀 𝑉
= 144 𝑔 240 𝑐𝑚3
= 0.6 𝑔 𝑐𝑚3

18. Sample Density Calculations
A liquid has a volume of 1.25 L. Its density is g/mL. Find the mass of the liquid.
1.25 L x 1000 = 1250 mL
M =D x V
= 𝑔 𝑚𝐿 x 1250 mL
= g

19. Density and States of Matter
solids usually have greater densities than liquids, which usually have greater densities than gases
KMT: particles in a solid are tightly packed together therefore there are more particles in a given volume than there are in a liquid having the same volume
exceptions: liquid mercury is more dense than many solids; at some temperatures, liquid water is more dense than solid ice (water is densest at 4 °C)
as you increase the temperature of a substance, its density decreases eg. lava lamp