Changes of state and the particle model Flashcards
What is state of matter ?
A physical property that describes matter as a solid, liquid, or gas
What is Change of state ?
A physical change of a substance from one state of matter to another
What is density ?
Density is the mass per unit volume of any object.
How do we calculate density?
Mass/volume
What are units of density ?
Kilogram per cubic meter
How do you find density of regular shaped object ?
1) Use a balance to measure its mass
2) measure length, width and height with a ruler
3) Calculate the volume using density = mass/volume
How do you find density of an irregular shaped object ?
1) Use balance to measure its mass
2) Fill eureka can with water
3) Place measuring cylinder under spout
4) Place object in water
5) Measure the volume of water collected in the measuring cylinder
6) Find density
How to find density of a liquid ?
1) Place a measuring cylinder
2) Pour 50ml of liquid into measuring cylinder
3) Record liquid mass
4) Find the density
Describe the solid state of matter
Tightly packed particles in fixed shape that moves by vibrating and they don’t have much energy
Describe liquid state of matter
Particles are held together but in a irregular pattern
More energy than particles in a solid
Move past each other in random directions at low speeds
Describe gases state of matter
They aren’t held close together
There are no forces between them
They have more energy than in solids and liquids
Constantly move in random directions at range of speeds
With changes of state why is mass is conserved ?
These changes in state are called physical changes because the process can be reversed (eg cooling instead of heating). This is different to the changes seen in a chemical reaction when the changes cannot be reversed so easily.
What is melting ?
From a solid to a liquid
What is boiling/evaporating ?
Liquid to gas
What is condensing ?
Change of state from a gas to a liquid
