6.1 When Substances Change Flashcards
In what type of change does a new substance form in?
Chemical change
Is a physical change reversible?
Usually it is
What may change in a physical change even though no new substance is formed?
The physical properties
What changes occur in physical changes?
Shape or form, expansion and contraction, change of state or mixing substances together.
How does an object change shape or form?
When force is applied, breaking, bending, stretching, crushing, twisting or compressing the object
When does expansion and contraction occur?
They occur when the temperature of the substance increases or decreases.
Does an object take up more or less space when heated?
More space
What happens to the volume when an object is expanded?
The volume increases, density decreases and no new substance is formed.
How does an object contract?
When it is cooled it contracts
What happens to the volume and density when an object is cooled?
The volume increases while the density decreases
What do thermometers use to show a temperature change?
The expansion and contraction of mercury and ethanol.
What happens to the state of an object if enough heat is applied to it?
It expands and changes state and the other way round if an object is cooled enough it contracts and changes state.
What change of state occurs in melting?
Solid to liquid
What change of state occurs in evaporation?
Liquid to gas
What change of state happens in condensation?
Gas to liquid