Unit 1.1 - states of matter Flashcards
Describe the 3 states of matter in terms of shape, volume and compression
Solids - fixed shape, fixed volume, cannot flow, cannot be compressed
Liquid - not fixed shape, fixed volume, can flow, cannot be compressed
Gas - not fixed shape, not fixed volume, can flow, can be compressed
Describe the arrangement and motion in the 3 states
Solid - regular arrangement, tightly packed and ordered. Vibrating in fixed positions
Liquid - no regular arrangement, close, particles are touching each other. Move/slide past each other in random directions with random speed but they frequently collide with other particles
Gas - random arrangement, far apart. Rapid random motion in all directions (still move at different speeds but much faster than liquids)
Define forces of attraction
Forces that exist between molecules that pull or attract the particles to each other
Describe the forces of attraction in the 3 states of matter
Solid - very strong
Liquids - strong/weaker than in solid
Gas - non-existent
Why do solids have a fixed shape and liquids don’t?
There are strong forces of attraction between particles in a solid, while in a liquid they are weaker which allows them to move more freely and lets the liquid change shape
Why can gases be compressed?
Because there is a lot of space between the particles
Define the kinetic particle theory
All matter is made of small particles that are in random motion and that have space between them
Define kinetic energy
A store of energy transferred when an object moves. Objects moving quickly have more kinetic energy than those moving slowly. Increased by temperature.
Explain why solids change to liquids with an increase of temperature
As the temperature rises, so does the kinetic energy of the particles. Before, they were vibrating around in a fixed position, but as the temperature continues to rise, they gain enough energy to overcome the forces of attraction and slide past each other
What happens to the temperature during change of state?
It remains constant/does not change because any heat being added is used to break apart the bonds between particles
When does evaporation occur and what does it produce?
Evaporation occurs below the boiling point of a liquid, only at the liquid’s surface. A gas formed below its boiling point is called vapour.
How does temperature affect volume of a gas?
A temperature increases means that the gas particles gain more kinetic energy. This makes them move faster and further, but still in random directions. This increases the distance between the particles, meaning that the volume they occupy increases
Define pressure
The amount of force applied to the surface of an object over a particular area
What happens when you increase the pressure of a gas at a fixed temperature?
The volume of a gas decreases, because it has the same number of particles with the same kinetic energy that need to apply more pressure
Describe how the air molecules exert a pressure on the wall of a tire
Due to the constant random motion of gas particles, the air molecules frequently collide with the walls of the tire. These collisions apply force on the walls due to the change in momentum of particles that occurs with each collision. Since pressure is defined “the amount of force applied to a surface over a particular area”, the collisions exerting force on the tire walls in turn causes them to exert a pressure on it.
