properties of matter Flashcards
what is specific heat capacity?
specific heat capacity is the amount of heat energy needed to increase the temperature of 1 kg of a substance by 1 degree
what is heat?
heat is a form of energy measured in joules. Heat is transferred between objects of different temperatures - always from the high temperature to the low temperature object
what is temperature?
Temperature is a measure of how hot or cold a substance is - it also tells us how much kinetic energy on average the particles in a substance have.
what happens to a solid substance as we heat it up?
when state changes temperature stays constant
the amount of heat energy required to increase the temperature of an object depends on
- the objects mass
- the type of material
- the desired increase of temperature
what is the specific latent heat of fusion?
the specific latent heat of fusion is the heat energy needed to change 1kg of a solid to liquid at the melting point
what is the specific latent heat of vapourisation?
The specific latent heat of vapourisation is the heat energy needed to change 1 kg of liquid to gas at the boiling point.
which is greater vapourisation or fusion?
latent heat is greater than latent heat of fusion as it takes more energy to change from a liquid to gas than from solid to liquid
what is pressure
pressure is the force acting over a given area
how can we decrease pressure?
to do decrease pressure we can increase the size of the area that the force acts over e.g snow shoes
how is an outwards pressure created by a gas in a container?
When gas particles collide with an area of the wall in a container that they are kept in they exert a force in the container walls causing an outwards pressure on the wall
what happens to pressure as volume is decreased?
As volume is decreased, pressure increases ( fixed mass of gas at a constant temperature)
as volume decreases particles have a shorter distance to travel before hitting the walls, collisions with the walls are more frequent. This results in a greater force exerted and an increase in pressure.
what happens to volume as temperature increases?
as temperature increases, the average kinetic energy of the particles increases and the particles move more quickly
Collisions with the walls are more frequent
if the container is free to expand then the volume will increase meaning the particles now have further to travel to collide with the walls - pressure remains constant
what happens to pressure as temperature increases
as temperature increases, the average kinetic energy of the particles increases and the particles move more quickly. Collisions with the walls are more frequent and more energetic. This results in a greater force exerted and an increase in pressure.
what is pressure?
the force acting over a given area
