States of Matter
What are the three common states of matter on Earth?
Solid, Liquid, and Gas
What happens to particle motion when temperature increases?
Particles move faster
What is thermal energy?
The total energy of moving particles in a substance
What is it called when a solid turns into a liquid?
Melting
When you see water droplets on a cold soda can, what phase change caused it?
Condensation
In which state do particles vibrate in place but stay close together?
Solid
What happens to the motion of particles when thermal energy is removed?
They slow down.
What type of energy transfer happens when you touch a hot metal spoon?
Conduction
What is condensation?
Gas changing into a liquid
Why does ice cream melt on a hot day?
It absorbs thermal energy from the air
Which state of matter takes the shape of its container but keeps a fixed volume?
Liquid
How does the kinetic energy of particles in a liquid compare to that of a gas?
It’s less in a liquid than in a gas
What happens to the temperature of a substance when it melts, even though energy is still being added?
The temperature stays the same while particles change state
What happens to the motion of particles during freezing?
They slow down and arrange into a fixed pattern
Why does your body sweat when you’re hot?
Evaporation of sweat removes thermal energy and cools the body
How are the particles arranged in a gas compared to a solid?
They are much farther apart and move freely
Why do gases have the most particle motion?
Because they have the most thermal energy and least particle attraction
Explain why adding thermal energy doesn’t always increase temperature.
Energy can go into changing the state instead of increasing particle speed
What two phase changes require adding energy?
Melting and evaporation (or sublimation)
How does a refrigerator remove thermal energy from food?
It transfers heat from inside to outside using a coolant system
What is plasma and where can it be found?
A high-energy state where atoms lose electrons; found in lightning and the Sun
Describe how adding heat affects the spacing and speed of particles in ice as it melts.
Particles move faster and farther apart as they break free from their fixed positions
Why does evaporation cause cooling?
Fast-moving particles escape, leaving slower ones behind with less energy
What phase change skips the liquid state completely?
Sublimation or deposition (depending on direction)
Describe how water moves through the water cycle using energy changes.
Evaporation adds energy, condensation removes energy, and freezing/melting involve transfers of thermal energy