Physics - Matter

What is the density triangle?

M
D V

What is it called when a substance changes from a solid to a liquid

melting

What is it called when a substances changes from a liquid to a gas

evaporation/transporation

What is it called when a substance changes from a gas to a liquid

condensation

What is it called when a substance changes from a liquid to a solid

freezing

What is it called when a substance changes from a solid to a gas

sublimation

What is it called when a substance changes from a gas to a solid

deposition

What does kinetic theory state

Everything is made of particles, and the movement and arrangement of these particles determine the properties of solids, liquids, and gases

Why do solids usually keep their shapes

Particles are held very closely together by strong bonds, which can vibrate but can’t move around

can solids usually be compressed

No

Why can liquids flow and take the shape of their container

The bonds between particles are not as strong as those in solids, and the particles are not arranged, so they can move around more and slide over each other

Can liquids usually be compressed? Why?

No - particles are still too close together

Why do gases expand to fit their container

THe particles have very weak bonds, and are constantly moving around quickly and randomly. Because of this, it is inevitable that they will diffuse to fill the container they are in

Can gases be compressed

Yes

Why does a change in state occur (less dense)? takes in/gives out energy. Affected by…?

Solid -> liquid ->gas
The particles have enough kinetic energy to break away from their fixed positions and move around
Takes in energy in the form of heat from the surroundings, and the remaining substance is left colder
Affected by: increase in temperature, increase in surface area

Why does a change in state occur (more dense)

Gas -> liquid -> solid
The particles do not have enough energy to continue moving around, and they cannot overcome the energy pulling them closer towards each other
Energy is released as the particles are pulled closer together, forming strong bonds
Affected by: decrease in temperature, decrease in surface area

How does evaporation work (not with heating)

Some of the particles in a liquid will have more or less kinetic energy than others.
Some particles may have enough energy to escape the intermolecular forces of attraction and therefore escape the liquid
When these particles escape, the average energy of the remaining liquid is lower because the evaporation has transferred energy away from the liquid

How does condensation work

Energy is released as particles move closer together, forming a liquid. This means that their kinetic energy is transferred to the environment as thermal energy

What factors can affect evaporation

Temperature
Surface area
Air movement

Describe particle arrangement in a solid

Particles are arranged in a consistent lattice structure, held together by strong intermolecular forces. They can vibrate, but can’t move, which means solids have a definite shape and volume

How does melting a solid work

Heat is applied → particles vibrate more strongly, weakening their intermolecular forces → at the melting point they have enough kinetic energy to escape these bonds and form a liquid

Describe the particle arrangement in a liquid

Weaker forces of attraction mean the particles can move freely. They are randomly arranged, but are still fairly close together. They have a definite volume but have no fixed shape so can flow to fit a container

How does boiling a liquid work (heating)

Heat is applied → particles gain kinetic energy so move around faster → weakens intermolecular forces of attraction → at the boiling point, the particles have enough energy to break the bonds altogether and form a gas

Describe the particle arrangement in a gas

Forces of attraction are very weak, so particles are free to move around and don’t keep a definite shape or volume. They will always expand to fill a container. Constantly moving with random motion

What happens when you heat up a gas

The particles gain kinetic energy and move around faster. If they are in an expandable container, then it will expand, if the container is fixed, then the pressure will increase

If a change of state happens in a closed system, does the mass change?

No

If a change of state happens in a closed system, does the density change?

Yes

What is density

How much mass a substance has per unit of its volume

How to find the density of a regular solid

Use a balance to measure the mass
Use a ruler to measure the length, width, height, radius, or any other measurements you need to find volume
Use the equation density = mass/volume to find the density

How to find the density of an irregular solid

Use a balance to measure the mass
Fill a eureka can just below the spout, and place a measuring cylinder underneath.
Place the object into the can and wait for all the water to drip out of the spout.
Measure the volume in the measuring cylinder
Use the equation density = mass/volume to find density

How to find the density of a liquid

Place a measuring cylinder onto a balance and 0 it
Pour in the liquid to measure its mass
Measure the volume on the measuring cylinder
Use the equation density= mass/ volume to find density

Hazards, risks, and errors and how you would mitigate them

Parallax error → read measuring cylinder from eye level
Random errors like not letting all the water drip out, not filling the eureka can to the right height, misreading measurement → complete practical multiple times and find a mean + eliminate anomalies
Broken glass → alert adult
Water spills → keep paper towels nearby