Particle Theory of Matter
What theory explains that all matter is made of tiny particles?
The Particle theory of matter
What do we call the substance that does the dissolving?
A solvent
What is a substance made of only one type of atom called?
An element
What is the formula for density?
Density = mass ÷ volume
What happens to pressure when a gas is compressed?
Pressure increases.
According to particle theory, what happens to particles when temperature increases?
They move faster.
What type of solution can still dissolve more solute?
An unsaturated solution
Is water an element or a compound?
A compound
What tool helps you remember how to calculate density, mass, or volume?
The density triangle
What happens to particle movement when temperature increases?
Particles move faster.
Which state of matter has particles that are far apart and move freely?
Gas
Why is water called the universal solvent?
Because it dissolves many substances.
Is water an element or a compound?
A compound
Which is more dense: an object with a lot of mass in a small volume or a small mass in a large volume?
A lot of mass in a small volume.
Why do aerosol cans have heat warnings on them?
Heating the gas inside makes particles move faster, increasing pressure and possibly causing the can to burst.
Using particle theory, explain why liquids can change shape but solids cannot.
Liquid particles can slide past each other; solid particles only vibrate.
Name one factor that increases the rate of dissolving.
Stirring / heat / smaller particles
What is the difference between a homogeneous and heterogeneous mixture?
Homogeneous looks the same throughout; heterogeneous has visible parts.
An object has a mass of 40 g and a volume of 10 cm³. What is its density?
4 g/cm³
What happens to a gas when it is heated inside a flexible container, like a balloon?
The gas particles move faster and the balloon expands (volume increases).
Explain how particle theory helps explain both dissolving (Grade 7) and pressure changes (Grade 8).
Particle movement and spacing explain how substances dissolve and how collisions create pressure.
Using particle theory, explain why sugar dissolves faster in warm water than cold water.
Particles move faster in warm water and collide more often.
Name a mixture and explain how it could be separated.
Example: sand and water → filtration (any valid example + method)
Using particle theory, explain why gases have a lower density than solids.
Gas particles are far apart with lots of empty space.
Explain why a balloon expands when heated using particle theory.
Particles move faster, collide more, and push outward.