t3-particle model

Question 1

what is density and what is the equation

Answer 1

mass per unit volume
p=m/v

Question 2

what is the unit for density

Answer 2

kg/m3

Question 3

describe particles in a solid

Answer 3

tightly packed
regular arrangement
vibrate around a fixed point

Question 4

describe particles in a liquid

Answer 4

random arrangement
flow over each other

Question 5

describe particles in a gas

Answer 5

no arrangement
move quickly in random directions
far apart

Question 6

which state of matter has the lowest density and why

Answer 6

gases because particles are further apart
they have more energy which increases volume but decreases density

Question 7

how to find the volume of an irregular shape

Answer 7

fill a displacement can with water
submerge object in can
water level rises
the displaced water spills out and is collected in a measuring cylinder
displaced water occupies same space as the object so their volumes are the same
use density formula to find density

Question 8

how does a change of state differ from a chemical change

Answer 8

in a change of state the materials can return to its previous state- the change can be reversed

Question 9

what is sublimation

Answer 9

solid changes into gas without going through liquid state

Question 10

what is condensation

Answer 10

gas changes to liquid

Question 11

what is the internal energy of a substance

Answer 11

the total kinetic and potential energy of all particles in a system

Question 12

how does heating affect the energy of a substance

Answer 12

heating transfers energy to substance
increases energy of the particles

Question 13

what 2 things can heating a substance do

Answer 13

raise temperature
change state

Question 14

what is specific heat capacity

Answer 14

energy needed to raise 1kg of a substance by 1 degree

Question 15

how does internal energy/temperature change when a substance changes state

Answer 15

internal energy increases/decreases
temperature is remains constant

Question 16

what is specific latent heat

Answer 16

energy needed to change the state of 1kg of a substance without a change in temperature

Question 17

what is specific latent heat of fusion

Answer 17

energy needed to melt/freeze the substance at its melting point

Question 18

what is specific latent heat of vapourisation

Answer 18

energy needed to boil/condense the substance at its boiling point

Question 19

how does temperature change gas particles’ average kinetic energy

Answer 19

higher temp=higher average kinetic energy

Question 20

what effect does increasing volume have on gas pressure at constant volume

Answer 20

pressure increases as temperature increases

Question 21

why does pressure increase as temperature increases

Answer 21

kinetic energy of particles increases
more frequent collisions
collisions with more force
therefore greater pressure

Question 22

describe the force that the pressure of a gas exerts on container walls

Answer 22

force acts at right-angles to the walls
force increases as pressure increases

Question 23

how does an increase in volume of gas decrease pressure

Answer 23

molecules are more spread out
time between collisions increases
reduces rate of collisions

Question 24

why does the temperature of air inside a bike pump increase when it is pumped

Answer 24

work is done on a gas when it’s compressed
doing work on a gas increases its internal energy which increases average kinetic energy of particles
temperature increases