Chapter 4 - Density Flashcards
1
Q
What is the definition of density ?
A
the mass of unit volume of a substance.
2
Q
What is the formula for density?
A
mass of object
density = —————————-
volume of object
3
Q
What is the symbol of density ?
A
p Greek symbol pronounced ‘rho’
4
Q
What is the unit of density ?
A
g/cm^3 or kg/m^3
5
Q
How do you find the density of an irregularly shaped object ?
A
1 - mass of the object found using top pan balance
2 - Use a eureka can
3 - the volume is the amount of water displaced
4 - Density calculated using the formula
6
Q
On a graph of mass against volume what does the gradient represent ?
A
The density of the particular substance
7
Q
Explain the kinetic theory of solids
A
- molecules are packed tightly together
- They vibrate about fixed positions
- have strong forces of attraction between them
- have a fixed shape, volume.
- have a high density
8
Q
Explain the kinetic theory of liquids
A
- molecules are close together
- molecules can move around in an direction
- forces of attraction still quite strong
- have a medium density
- fixed volume but take the shape of the container
9
Q
Explain the kinetic theory of gases
A
- molecules are very far apart
- molecules move around very quickly in all directions
- weak forces of attraction between molecule
- low density
- always completely fill their container
