A change in size, shape, or state without forming a new substance
What is a physical change?
Does a physical change create a new substance?
No
Q: Change from solid to liquid
A: Melting
Q: What is the melting/freezing point of water?
A: 0°C
Q: Ice cream melting on a hot day is what type of change?
A: Physical change
When a substance spreads evenly in another substance
What is dissolve?
Q: Name one property that can change in a physical change
A: Size, shape, or state
Q: Change from liquid to gas at the surface
A: Evaporation
Q: What is the boiling point of water at sea level?
A: 100°C
Q: Salt disappearing in water is called what?
A: Dissolving
The temperature at which a solid turns into a liquid
What is melting point?
Q: Is melting ice reversible or irreversible?
A: Reversible
Q: Change from gas to liquid
A: Condensation
Q: What happens to boiling point at higher elevation?
A: It decreases
Q: Dry ice turning into gas is an example of what?
A: Sublimation
When a solid changes directly into a gas
What is sublimation?
Q: Cracking an egg—is it easy to reverse?
A: No (irreversible physical change)
Q: Change from gas directly to solid
A: Deposition
Q: What happens to freezing point when salt is added?
A: It decreases
Q: Fog forming over water is what process?
A: Condensation
The temperature at which a liquid turns into a gas
What is boiling point?
Q: Name the 3 types of physical changes
A: Shape/size, mixing, change of state
Q: What type of energy causes changes of state?
A: Thermal energy
Q: What happens to boiling point when solute is added?
A: It increases
Q: Why does pasta take longer to cook in the mountains?
A: Lower boiling point of water