3. Particle Model Of Matter Flashcards
What is a particle?
The smallest part of a substance, usually either an atom or molecule.
How are the particles arranged in a solid?
-neatly ordered
- tightly packed
- vibrate around a position
- very strong forces between molecules
- can’t be compressed
How are the particles arranged in a liquid?
- not neatly ordered, but moving
- strong forces between molecules
- can’t be compressed
- still close together
- empty spaces
How are particles arranged in a gas?
- mostly empty space
- can be compressed
- no order
- weak forces between molecules
- random movement in all directions
What are the limitations with the particle diagram?
- not all particles are the same size
- not all particles are spheres
- forces between particles are not shown
What is the difference between boiling and evaporation?
Boiling only happens at the boiling point but evaporation only happens on the surface and happens at any temperature.
What is melting?
When a substance changes from a solid to a liquid.
What is freezing?
When a substance changes from liquid to solid.
What is boiling?
When a substance changes from liquid to gas.
What is evaporating?
When a substance changes from liquid to gas.
What is condensing?
When a substance changes from gas to liquid.
What happens in melting?
The surroundings transfer energy to the solid so its particles vibrate faster. Particles move away from their place in the pattern. They continue to move around until the substance melts and becomes a liquid.
What happens in freezing?
The substances particles begin to move more slowly as they transfer energy to their surroundings. The particles get into a pattern and vibrate on the spot. Eventually the liquid becomes a solid.
What happens in boiling?
As the liquid is heated the particles gain energy and move around more. Some particles have enough energy to leave the others. Bubbles of the substance form in the gas state throughout the liquid. They rise to the surface and escape.
What happens in evaporating?
In a liquid some particles have more energy than others. The particles with the most energy leave the liquid surface. They then move away from their liquid. The particles spread out, forming a gas and they mix with air particles.
What happens in condensing?
The particles in a gas have different energies. Some may not have enough energy to remain as separate particles, particularly if the gas cooled down. They come closer together until they are touching and form a liquid.
What are the units in the equation mass = density x volume
Density = kg/m3 or g/cm3
Mass= kg/ g
Volume= m3/ cm3
How do you calculate the volume of a regular object?
Length x width x height
How does conduction work?
- Heat is applied to one particle
- Particles start to vibrate, spreading the thermal energy
- Finally all particles contain energy and heat
How does convection work?
- Heat is applied
- Hotter, less dense water rises
- Cooler, more dense water sinks and gains heat
What type of absorber and emitter of infrared radiation is the colour black?
Black is a good absorber and emitter of infrared radiation.
What type of absorber and emitter of infrared radiation is the colour white?
White and shiny surfaces are good at reflecting infrared radiation and are poor emitters of infrared radiation.
Why are copper pipes painted black?
Black is a good absorber and emitter of infrared radiation. This allows the water to be heated due to the fast speed.
What is potential energy?
Potential energy of the particles is due to their positions relative to each other (intermolecular forces and chemical bonds). Solids have the greatest potential energy store and gases have the lowest out of the 3 states. Gases however have the greatest kinetic energy store and solids have the lowest out of the 3 states.
What happens if internal energy increases?
You either have a change in temperature or a change in state.
What energy makes up internal energy?
Potential energy and kinetic energy stores.
What does the temperature reached by the substance depend on?
- the mass of the heated object
- the energy input
- the material being heated
What are the units for the equation energy transferred= mass x specific heat capacity x change in temperature?
Energy transferred= joules (J)
Mass= kg
Specific heat capacity= J/kg degrees celsius
Change in temperature= degrees celsius
What is specific heat capacity?
The amount of energy needed to raise the temperature of 1kg of a substance of 1 degree celcius
What are the units of energy transferred= power x time
Energy transferred= joules (J)
Power= watts (W)
Time= seconds (s)
What is specific latent heat?
The amount of energy needed to change 1kg of a substance from one state to another without changing its temperature.
What is specific latent heat of fusion?
Specific latent heat between a solid and liquid (melting or freezing)
What is specific latent heat of vaporisation?
Specific latent heat between a liquid and gas (evaporating, boiling or condensing)
What are the units of the equation energy = mass x specific latent heat
Energy = joules (J)
Mass= kg
Specific latent heat= J/kg
What happens when a state changes through boiling or melting?
- an increase in thermal energy
- an increase in kinetic energy
- decrease in forces between particles
What happens when a state changes through condensing ore freezing?
- decrease in thermal energy
- decrease in kinetic energy
- increase in forces between particles
What are the units in force = pressure x area
Force= newtons (N)
Area = m3
Pressure = pascals (Pa)
What is Boyles law with units?
P1 x V1 = P2 x V2
Pressure= pascals (Pa)
Volume = m3
