P1 SB Heating Flashcards
Heat flows as a result of ____ differences. The greater the temperature difference the ____ the rate of thermal energy transfer. When objects reach the same temp we say they are in ____ ____
Temperature
Faster
Thermal equilibrium
Heat is measured in?
Joules
Different substances increase / decrease temps at different rates because…
They have different specific heat capacities
The specific heat capacity of a material is…
The quantity of energy ( J ) needed to raise the temperature of 1kg of that substance by 1 degree C
The higher the specific heat capacity, …
The more energy the material can hold
The longer it will take to heat up / cool down
Equation (provided in exam):
Energy = mass x specific heat capacity x temp change
What is this in symbols?
E = m x c x triangle T
Mass is conserved when a substance changes state because…
The number and type of atoms / molecules does not change
Physical changes eg changes of state are _____ - their original properties can be recovered
Reversible
Chemical changes eg lighting a match (combustion) are ___ - it is impossible to reverse them
Permanent
Name 2 examples of physical changes
Any 2 from:
Ice cream melting
Boiling water
Melting candle wax
Making ice cubes
Name 2 examples of chemical changes
Any 2 from:
Adding acid to alkali
Fireworks
Driving a car
Frying an egg
Lighting a match
Baking a cake
Specific latent heat is…
The energy needed to break intermolecular bonds and cause a change of state of 1kg of a material
Equation (provided in exam):
Energy = mass x specific latent heat
What is the symbol equation?
E = mL
