Heating Matter Flashcards
What is the definition of density? State the relevant
equation with units.
● The mass per unit volume of a material
● ⍴=m/v
● Density (kg/m³) = Mass (kg) / Volume (m³)
What is meant by a state of matter?
A form in which matter can exist, based on the particle arrangement in a substance
State the different states of matter in order (least to
most) of density of atoms
● Least dense: Gas
● Liquid
● Most dense: Solid
Use kinetic theory to explain the structure of liquids.
The particles have some kinetic energy.
They are free to move and can move
around in random directions at very slow
speeds.
Explain the movement of particles in a solid
The particles vibrate around a fixed
position as they do not have enough
kinetic energy to move freely
Describe the structure of particles in a gas
Particles in a gas have almost no forces
between them therefore they are completely
free to move, and move at high speeds in
random directions.
What is always conserved when a substance
undergoes a change of state?
Mass
How does a change of state differ from a chemical
change?
In a change of state, the material can
return to having its previous properties if
the change is reversed
What is the internal energy of a substance?
● The energy stored by the particles
●The sum of the total kinetic and
potential energies that make up the
system
What two things can heating a substance do?
- Raise its temperature
2. Change the state of the substance
What three factors determine the
temperature change of a system?
- Mass of substance being heated
- Type of material (Specific heat
capacity) - Energy inputted into the system
What is sublimation?
When a solid turns directly into a gas
What is the difference between physical changes
and chemical changes in substances?
Physical changes can be reversed.
Chemical changes cannot be easily
reversed
How does heating cause a substance to
change state?
Heating matter gives particles more potential
energy. This energy is used to break the bonds of
attraction, leading to a change of state.
Why does heating increase the temperature of
substance?
It increases the amount of thermal energy in
that substance. It also gives the particles
more kinetic energy, meaning they move
faster and their temperature increases
