Physics - 6 Molecules and Matter - 6.1 Density & 6.2 States of Matter & 6.3 Changes of State & 6.4 Internal Energy

Density

(of an object) its mass per unit volume

Density =

mass ÷ volume

ρ =

m ÷ V

Density is measured in...

kg/m³

Measure density of solid

- find mass with electronic balance
- find volume

Volume of regular object

use ruler to find length, width and depth and calculate volume

Volume of irregular object

thread it on a string a submerge it in water; measure the displacement

Eureka can

used to measure volume of irregular object

Mass of liquid [3]

- find mass of empty container
- add liquid
- find mass of container and water

Volume of liquid

measuring cylinder

Changes of state are...

physical changes

... stays the same during a change of state

temperature

Changes of state graph

Latent heat

the energy absorbed or released during a change in state

Internal energy

the sum of the kinetic (in relation to each other) and potential energies of all particles in the system

Internal energy does not include [2]:

- gravitational potential energy
- kinetic energy caused by motion of whole substance

Sublimation

solid to gas