P6 - Molecules and Matter Flashcards
What is a boiling point?
temperature at which a pure substance boils or condenses
What is density?
mass per unit volume of a substance
What is freezing point?
the temperature at which a pure substance freezes
What is internal energy?
The energy of the particles of a substance due to their individual motion and positions
What is latent heat?
the energy transferred to or from a substance when it changes state
What is melting point?
The temperature at which a pure substance melts
What is physical change?
a change in which no new substances are produced
What is pressure?
force per unit cross-sectional area for a force acting on a surface at right angles to the surface. The unit for pressure is the pascal (Pa) or newton per square metre (N/m²)
What is specific latent heat of fusion Lf?
energy required to change 1kg of a substance from a solid to a liquid with no change in temperature
What is specific latent heat of vaporisation Lv?
energy required to change 1kg of a substance from a liquid to a gas with no change in temperature
A block of aluminium occupies a volume of 16cm³ and has a mass of 20.5g. What is the density?
1.3g/cm³
Calculate the volume of a chemical that has a mass of 3g and a density of 3g/cm³
1cm³
Gold has a density of 19g/cm³, Silver has a density of 10g/cm³. An Olympic medal has a volume of 80cm³. Which medal has the greatest mass?
Gold = 1520g
Silver = 800g
Gold medal has a greater mass
What is a solid?
A solid is a substance with a fixed shape and volume, it is more dense than gases and liquids. it cannot flow, It’s particles can only vibrate. It cannot be compressed. It’s particles are very close together and are fixed in a rigid arrangement
What is a liquid?
A liquid is a substance with no fixed shape but with a fixed volume, they are less dense than a solid but more dense than a gas. They can flow. They cannot be compressed. It’s particles are close together but are not fixed in a rigid arrangement, they are free to move
What is a gas?
A gas is a substance with no fixed shape or volume, it is less dense than solids and liquids and it can flow. It can be compressed. It’s particles are far apart.
What is the change from solid to liquid called?
melting
What is the change from liquid to solid called?
solidification
What is the change from liquid to gas called?
vaporisation
What is the change from gas to liquid called?
condensing
What is the change from gas to solid called?
deposition
What is the change from solid to gas called?
sublimation
What is the difference between boiling and evaporating?
Boiling is when all the particles have enough energy to turn into gas, evaporation is when only the particles at the surface have enough energy to turn into a gas.