The density of a material is a measure of the amount of matter in a given volume. | Density Definition |
What is density a measure of? | The amount of matter in a given volume. |
Density is measured in kilograms per cubic metre (kg/m³). | Density Units |
In what units is density measured? | Kilograms per cubic metre (kg/m³). |
The density of a material can be calculated using this equation: | Density Calculation Equation |
What equation is used to calculate density? | Density = Mass / Volume |
For example, we can calculate the density of an object with a mass of 300 kg and a volume of 25 m³. | Density Example 1 |
How can we calculate the density of an object with a mass of 300 kg and a volume of 25 m³? | Density = 300 kg / 25 m³ = 12 kg/m³ |
To calculate the density of 100 cm³ of gold with a mass of 1.93 kg, first convert the volume into cubic metres. Remember, 1 m³ = 1,000,000 cm³. | Converting Volume Units |
How do we convert 100 cm³ to cubic metres? | 100 cm³ = 100 / 1,000,000 m³ = 0.0001 m³ |
We then plug the values into the formula: Density = Mass / Volume | Density Example 2 Calculation |
How do we calculate the density of gold with a mass of 1.93 kg and a volume of 0.0001 m³? | Density = 1.93 kg / 0.0001 m³ |
The density of an object depends on how close its particles are to each other. | Density and Particles |
What does the density of an object depend on? | How close its particles are to each other. |
The kinetic theory model shows how particles are arranged in each state of matter. | Kinetic Theory Model |
What does the kinetic theory model show? | How particles are arranged in each state of matter. |
The states of matter are solid, liquid, and gas. | States of Matter |
What are the three states of matter? | Solid, liquid, and gas. |
In a solid, particles are very close together and the forces of attraction between them are strong. | Solid State Particles |
How are particles arranged in a solid state? | Particles are very close together with strong forces of attraction between them. |
The solid state has the highest density. Particles don't move around but vibrate in fixed positions. | Density of Solids |
Which state of matter has the highest density and why? | Solid, because particles are very close together and vibrate in fixed positions. |
In a liquid, particles are quite close together. | Liquid State Particles |
How are particles arranged in a liquid state? | Particles are quite close together. |
The forces of attraction between particles in a liquid are weak, so they can move around. This makes liquids less dense than solids. | Density of Liquids |
Why are liquids less dense than solids? | Because the forces of attraction between particles are weak, allowing them to move around. |
In a gas, particles are far apart and move constantly in random directions due to no forces of attraction between them. | Gas State Particles |
How are particles arranged in a gas state? | Particles are far apart and move in random directions with no forces of attraction between them. |
This makes gases even less dense than liquids. | Density of Gases |
Why are gases less dense than liquids? | Because particles are far apart and move randomly due to the lack of attractive forces. |
When an object changes between being solid, liquid, or gas, it changes state. | State Change |
What happens when an object changes between being solid, liquid, or gas? | It changes state. |
Changes of state are physical changes, which means they are reversible. | Physical Changes |
What type of changes are state changes and are they reversible? | Physical changes, and they are reversible. |
Physical changes are different from chemical changes, which cannot easily be reversed. | Chemical Changes |
How are physical changes different from chemical changes? | Chemical changes cannot easily be reversed. |
If the substance changes back into its original state, it gets back its original properties. | Original Properties |
What happens to a substance's properties if it changes back into its original state? | It gets back its original properties. |
When substances change state, mass is conserved. The mass before a state change is equal to the mass after the state change. | Mass Conservation in State Changes |
What happens to mass when substances change state? | Mass is conserved; the mass before a state change is equal to the mass after the state change. |