PNM Flashcards
state the Kinetic Theory of Matter
all matter is made up of numerous tiny particles in continuous random motion
what is Brownian motion?
the random movement of particles suspended in a liquid or gas
state the shape, volume, ease of flow and compressibility of solids
solids:
- have fixed shape
- have fixed volume
- do not flow
- are not compressible
state the shape, volume, ease of flow and compressibility of liquids
liquids:
- have no fixed shape, they take the shape of the container
- have fixed volume
- can flow
- are not compressible
state the shape, volume, ease of flow and compressibility of gases
gases:
- have no fixed shape, they take the shape of the container
- have no fixed volume
- can flow
- are compressible
draw 2D particle diagrams for a solid, liquid and gas
solid: min. 9 particles, regular pattern, should fill up entire box (touch all sides of box), should touch each other
liquid: min. 9 particles, no regular pattern, some particles must touch boundaries of box, should touch each other
gas: min. 5 particles, no regular pattern, particles can be separate from each other, do not have to touch boundaries of box
note: all particles must be the same size.
state the arrangement of particles, motion of particles, and forces of attraction between particles in a solid
arrangement: particles arranged in a fixed, regular pattern, packed closely together.
motion: particles vibrate about fixed positions.
forces of attraction: strong forces of attraction between particles.
state the arrangement of particles, motion of particles, and forces of attraction between particles in a liquid
arrangement: particles are free to move. no fixed positions, no regular pattern. particles further apart than in a solid, closer together than in a gas.
motion: particles slide freely past one another and can change positions.
forces of attraction: weaker forces of attraction than in solid, stronger than in gas.
state the arrangement of particles, motion of particles, and forces of attraction between particles in a gas
arrangement: particles are free to move. no fixed positions, no regular pattern. particles very far apart.
motion: particles move freely and randomly at high speeds, occupying any available space.
forces of attraction: negligible/very weak forces of attraction between particles.
what influences the shape & volume of a substance, as well as whether it can flow?
hint: based on Kinetic Theory of Matter
motion of particles
what influences the compressibility and density of a substance?
hint: based on Kinetic Theory of Matter
distance/arrangement of particles
why do solids have a fixed shape while liquids and gases do not?
hint: answer based on Kinetic Theory of Matter
particles in a solid can only vibrate about fixed positions while particles in a liquid can slide freely past one another and change positions, and particles in a gas move freely and randomly at high speeds to occupy any available space
why can gases be compressed while solids and liquids cannot?
hint: answer with Kinetic Theory of Matter
the particles in a gas are very far apart and occupy any available space, while the particles in a solid are packed closely together, and the particles of a liquid are further apart than in a solid, but closer together than in a gas
in the heating curve of pure water:
describe what happens to particles before and during melting
before melting: as thermal energy is absorbed by particles, they vibrate more vigorously about fixed positions and temperature increases.
during melting: at the melting point, even though thermal energy is still being absorbed by the particles, temperature remains constant. this is because all the thermal energy is used to overcome forces of attraction between the particles until the ice completely melts.
in the heating curve of pure water:
describe what happens to particles before and during boiling
before boiling: as thermal energy is being absorbed by particles, they slide freely past one another at higher speeds and temperature increases.
during boiling: at the boiling point, even though thermal energy is still being absorbed by particles, temperature remains constant. this is because all the thermal energy is used to overcome forces of attraction in the liquid until it completely boils.
in the cooling curve of pure water:
describe what happens to particles before and during condensation
before condensation: as thermal energy is lost by particles, they move freely and randomly at decreasing average speeds, and thus temperature decreases
during condensation: at the condensation point, temperature remains constant even though thermal energy is still being lost to the surroundings. this is because as forces of attraction between particles in a gas increase, particles come closer together and heat is released. all the thermal energy released by the substance is lost to the surroundings, thus temperature remains constant.
in the cooling curve of pure water:
describe what happens to particles before, during and after freezing
- before freezing: as thermal energy is lost before the freezing point is reached, particles slide past one another freely at slower average speeds, thus temperature decreases.
- during freezing:at the freezing point, even though thermal energy is still being lost to the surroundings, temperature remains constant.
- as the forces of attraction between particles increase, particles are drawn into a fixed, closely packed state, and heat is released.
- all the thermal energy released by the substance is lost to the surroundings and hence temperature remains constant.
- after freezing: as thermal energy is lost by the substance, particles vibrate about their fixed positions at slower average speeds, causing temperature to decrease
using Kinetic Theory of Matter, explain how expansion of a metal ball occurs upon heating
as the ball is heated, the particles in the ball gain more energy and vibrate more vigorously about their fixed positions, so the distance between particles increases, and thus the volume of the ball increases, leading to the ball expanding.
using Kinetic Theory of Matter, explain how the contraction of a metal ball occurs upon cooling
as the ball is cooled, particles in the ball lose energy and vibrate less vigorously about their fixed positions, so the distance between particles increases, and the volume of the ball thus decreases, leading to the ball contracting.
