States of Matter
What are the three main states of matter?
Solid, liquid, and gas
What happens to the temperature of a substance while it melts?
It stays the same until all of it has melted.
What happens to particle motion when energy is added to a substance?
The particles move faster.
What is the melting point of water?
0°C
What is temperature a measure of?
The average kinetic energy of particles.
Which state of matter has a definite shape and definite volume?
Solid
What is the process called when a solid changes to a liquid?
Melting
What happens to particle motion when energy is removed?
The particles move slower.
What is the boiling point of water?
100°C
What is thermal energy?
The total energy of all the particles in a substance.
Which state of matter has a definite volume but takes the shape of its container?
Liquid
What is the process called when a liquid changes to a solid?
Freezing
Define kinetic energy.
The energy of motion.
What happens to temperature during boiling?
It stays the same until all liquid becomes gas.
How can two objects have the same temperature but different thermal energy?
If one has more mass (more particles).
What is the state of matter with no definite shape or volume?
Gas
What is condensation?
The process when a gas changes to a liquid.
Define potential energy.
Stored energy due to the position or attraction between particles.
Why do different substances have different melting points?
Because particle attraction strength varies.
When kinetic energy increases, what happens to temperature?
Temperature increases.
Describe how particles move in each state of matter.
Solids vibrate in place, liquids slide past each other, gases move freely and spread out.
What happens to energy during condensation?
Energy is released as particles slow down and move closer together.
When a solid melts, does its kinetic energy or potential energy increase? Explain.
Potential energy increases because particles move farther apart.
True or False: Melting and freezing points of a substance are the same.
True
Explain the difference between thermal energy and temperature using an example.
A bathtub of warm water has more thermal energy than a cup of hot water, even though its temperature is lower.