P6: Molecules And Matters Flashcards
What is internal energy?
A substance that is combined energy of kinetic and potential energy of the particles in a substance (or system)
What happens when you increase the internal energy of a substance?
1.Heating substance will increase particles of kinetic energy and overall internal energy causes increase if temp
2. Chanfe of state causes change in potential energy of particles overall internal energy
Solids to a liquid
- strong forces of attraction between particles causing remain in fixed positions
- Each particles vibrate in ficed positions
- More energy particles vibrate and given enough energy can break away changing liquid state
Liquid to a gas
- weaker forces attraction between particles in a liquid than solid
- weaker forces unable hold substances in rigid structure enough to stop leaving substance surface
- given enough energy are able to break away forces change gas state
Gas
- Forces holding particles together extremely weak allows particles to kove at high speed
- Particles collide each other and results in a ‘pressure’ being exerted
What happens if a gas is given more energy.
- When gas is heated provides more energy
- gaining more kinetic energy and move faster therefore collide with surfaces
- therefore the pressure exerted by the gas increases
What is the unit of energy?
Joules (J)
What is the equation for specific heat capacity?
Specific hear capacity (J/Kg) = number of joules of heat (E) / numb of kg of mass (m) x numb of C° of temperature change
What is the equation for density?
Density (P) = mass (m) / velocity (v)
What is the kinetic theory of matter - SOLID
particles in a solid held together by strong forces of attraction and vibrate their position. At low temperatures the vibrations are small and considered fixed
What is the Kinetic theory of matter - LIQUID
Intermolecular forces are too weak to keep particles in fixed position and free to move, move randomly therefore liquids flow
What is the kinetic theory of matter - GASES
particles in a gas are constant random motion so they are weak forces. Particles are spaced futher apart in liquids
What is evaporation?
Particles moving and bumping into each other. Particles at a liquids surface gain enough energy to leave surface as gas
How can we increase the rate of evaporation?
Increasing the surface area of liquid.
•Increasing the temperature of the liquid.
•Creating a flow of air across the liquid’s surface.
What is condensation?
Water molecules that are in the air hit cool surface, cool down and therefore stay condense change state from gas to liquid
