3: PARTICLES

Question 1

how to calculate the volume of an irregular object (4)

Answer 1

1. measure mass first
2. fill eureka can up to spout
3. submerge object using string and wait for all water to spill out into beaker
4. pour water into measuring cylinder to measure the volume (be at eye level)

Question 2

solid vs liquid vs gas

Answer 2

solid: particles vibrate in fixed positions, cannot be compressed
liquid: no regular arrangement and can move past eachother
cannot be compressed
gas: far apart, move at random speeds in random directions
can be compressed

Question 3

what is it called when a solid goes directly to a gas

Answer 3

sublimation

Question 4

what is needed to melt or evaporate?

Answer 4

energy to break strong electrostatic forces of attraction between particles

Question 5

what is latent heat

Answer 5

the energy needed to change the state of 1kg of a substance

Question 6

why does temp stay constant during a change of state?

Answer 6

if temp is increasing, particles are gaining kinetic energy
if temp stays the same, particles are gaining potential energy

Question 7

what happens when you heat a gas

Answer 7

the particles gain kinetic energy, and so they collide quickly and with more force, exerting an outward force and increasing the pressure

Question 8

what happens if gas is compressed at a constant temp

Answer 8

volume decreases

Question 9

how do you compress a gas

Answer 9

exert a force on it: called doing work on a gas

Question 10

what is the definition of internal energy

Answer 10

the sum of kinetic and potential energy of all particles in a substance

Question 11

what are the 3 ways to increase gas pressure

Answer 11

heat it, more kin energy, more collision
more gas, more collision
reduce volume/compress, more collision