Particles theory
Density= mass/ volume (p=m/v)
Required practical (measure density of irregular object)
1. Measure the mass of the object with a balance scale and record it
2. Fill a eureka can to the top of the notch
3. Tie a thin piece of string to the object and slowly lower it down to the can (avoid spill)
4. Catch the displaced water with measuring cylinder and record volume
5. Calculate density with p=m/v
Internal energy
- Sum of all particles’ kinetic energy and potential energy
- Gas; internal E always kinetic
- Heating increases internal energy
1. Gas
- Widely spaced
- Randomly arranged
- Rapid, random motion
- No force between particles (weak Van der Waal force)
- No potential energy
- Rapid, random motion (faster than liquid)
- Move at range of speed (avg speed linked to
temperature)
2. Solid
- Fixed positions
- Regular arrangement
- Vibrate about fixed points
- Closely packed
- Strong forces between particles
- Negative potential energy (attractive force)
- When heated; particles vibrate more strongly + move
slightly further apart
3. Liquid
- Particles move around randomly but not totally freely (maintain
in contact)
- Close together
- Random but not fixed arrangement
- Strong forces between particles (less than solid)
- Negative potential energy in between (force is
attractive)
- Particles at a range of speed
- When heated; particles speed up and spacing between
increases slightly
Density= mass/ volume (p=m/v)
Required practical (measure density of irregular object)
1. Measure the mass of the object with a balance scale and record it
2. Fill a eureka can to the top of the notch
3. Tie a thin piece of string to the object and slowly lower it down to the can (avoid spill)
4. Catch the displaced water with measuring cylinder and record volume
5. Calculate density with p=m/v
Internal energy
- Sum of all particles’ kinetic energy and potential energy
- Gas; internal E always kinetic
- Heating increases internal energy
1. Gas
- Widely spaced
- Randomly arranged
- Rapid, random motion
- No force between particles (weak Van der Waal force)
- No potential energy
- Rapid, random motion (faster than liquid)
- Move at range of speed (avg speed linked to
temperature)
2. Solid
- Fixed positions
- Regular arrangement
- Vibrate about fixed points
- Closely packed
- Strong forces between particles
- Negative potential energy (attractive force)
- When heated; particles vibrate more strongly + move
slightly further apart
3. Liquid
- Particles move around randomly but not totally freely (maintain
in contact)
- Close together
- Random but not fixed arrangement
- Strong forces between particles (less than solid)
- Negative potential energy in between (force is
attractive)
- Particles at a range of speed
- When heated; particles speed up and spacing between
increases slightly
