P3 Flashcards
What are the three states of matter?
Solids
Liquids
Gases
What is particle theory?
All things are made up of tiny balls (called particles) you can explain matter by how these balls move and the forces between the,
What is a solid?
Have strongforces of attraction hold the particles close in a fixed , regular arrangement. Particles dont have much energy so they can only vibrate about their fixed positions
What is a liquid?
Weaker forces of attractjon between particles. The particles are close together , but can move past each other and form irregular arrangements. They have more energy than the particles in a solid , they move in random directions at a low speed.
What are gases?
Almost no forces of attraction . The particles have more energy than in liquids and solids. They’re free to move , and are constantly moving in random directions and speed
What is the temperature related too in a gas?
The average kinetic energy of the particles in the gas. Higher the temperature , the higher the average energy.
Features of gas particles?
- free to move around. As they move they bang into each other and what ever else gets in the way.
- when they collide with something , they exert a force
- pressure is the force exerted per unit area
- in sealed contain , outward gas pressure is the total force exerted by all of the particles in the gas on a unit area of the container walls
What happens if you increase the temperature of a gas?
Transfers energy into the kinetic energy store of its particles
What happens if the kinetic energy of particle increases?
The speed of the particles increases
How does temperature effect pressure?
Increase in temperature increases pressure
How is there an increase in oressure when a gas is heated?
Particles travelling quicler , means they hit the sides of the container more often
-each particle also has a larger momentum which means they exert a larger force when they collide.
Equation for density?
Density = mass /volume
What is density?
The compactness of a object. Relates to the mass off a substance to how much space it takes up.
What is the unit of density?
Kg /m^3 or g/m^2
What does the density of a object depend on?
What it is made off and how its particles are arranged
How particles of dense material are arranged?
- particles packed tightly together.
- if you compress the material , its particles move closer and increase density
How does density vary?
Different woth each state of matter. Solids ar generally denser than liquids, and hases are usually less dense than liquids
What do particles in a system do?
Vibrate or move around , because they have kinetic energy stores. Also have energy in potential energy stores depending on their position
Where is energy stores in a system?
Stored by its particles(atoms and molecules)
What is the internal energy of a system?
Total energy that its particles have in their kinetic and potential energy stores
How to increase the internal energy?
Heating the system transfers energy toits particles they gain kinetic energy and move faster , increasing the internal energy. This leads to an increase in temperature or state
What does the temperature change depend on if a substance is heated?
Depends on the mass of the substance, what its made off(specific heat capacity) and energy input.
When does a change of state occur?
If a substance is heated enough - particles will have enough energy in their kinetic energy stores to break bonds holding them togetehe
What happens when you cool something?
Loses energy and forms bonds
Solid to a liquid?
Melting
Liquid to a solid?
Freezing
Solid to a gas?
Sublimating
Gas to liquid?
Condensing
Liquid to a gas?
Boiling or evaporationg
What happens when a change of state occurs?
Physical change rather than chemical . This means you dont end up with a new substance. It is the same substance just in a different form. If you reverse a change of state the substance will return to its original form. Number of particles does not change , they are just arranged differently , this means mass is conserved.
How is mass conserved?
Doesnt change during changes of state.
Change in thermal energy equation?
Mass x specific heat coacity x temperature change
What is the specific heat capacity ?
Amount of wnergy required to raise the temperature of on kilogram of the substance by one degree celcisus. How difficult it is to heat something up.
What is the specific latent heat capacity ?
Amount of energy required to change the state of on kilogram of the substance with no change in temperature
How to work out the specific latent heat capacity
Mass x specific latent heat
What is the latent heat of a substance?
Energy needed for a substance to change state
What happens when a change of state occurs in terms of energy?
Energy supplied changes the energy stores(internal energy , but not the temperature .
What is the specific latent heat of fusion?
Energy needed to change state from a solid to a liquid
What is the specific latent heat of vaporisation?
Energy required to change state form a liquid to a gas
