Physics: Particle Model of Matter (P3)

solid

strong forces of attraction hold the particles close together

fixed regular arraignment

vibrate in fixed positions

liquid

weaker forces of attraction

particles can move past eachother irregular arraignment

move in random direction at low speed

density = (units)

mass / volume kgm

measuring density (solid)

use a ______. Measure it’s ____. Measure l x w x h to calculate volume, use density = ___ / ____

balance mass mass volume

measuring density (irregular solid)

measure the ___ fill a ____ ___ with water . The water ____ ____ it , this is equal to the ______ of the object . use density = ____ / ____

balance eureka can displaced measure volume mass volume

measuring density (liquid)

place a _____ ____ on a _______. Zero the ______. Pour ___ml of liquid and ____ it’s mass . Repeat this until the cylinder is ______ . For each measurement use density = mass / volume. take an ______ and you will get the density

measuring cylinder balance balance 10 record full average

internal energy is defined as

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

heating the system transfers

energy to it’s particles increasing their internal energy causing a change in temp or state

the size of the change depends on …

mass SHC and energy input

specific/ latent heat

amount of energy needed to change 1kg of a substance from one state to another without a change in temperature

when a substance is melting/boiling energy is still being ____ in so the ______ _____ is _____this _____ is used to ____ the _____between the particles.

the energy is used to …

put internal energy increasing energy break bonds

break bonds between particles not change the temperature

What happens when a substance is condensing or freezing?

bonds forming between particles which releases energy

internal energy decreases but temperature doesn’t go down until all substance turned to liquid or solid

specific latent heat formula

energy = mass x specific latent heat

fusion

vaporisation

solid to liquid liquid to gas

particles in a gas move in …

random directions and random speeds

when the temperature of gas is increased energy is transferred into the _______ energy store

kinetic

why would a water tank explode ?

• Gas pressure is caused by particles colliding with the walls of the water tank.

• Heating increases particle speed, leading to more frequent and more forceful collisions.

• With the volume of the tank constant, this results in increased pressure.

• If the pressure becomes too high, it can cause the container to explode.

pressure is _____ ____ to ____

boyle law

inversly proportional volume p1v1=p2v2

"Explain how gas pressure creates a net force on the walls of a container, and what happens if the container can change size

nett outward force at right angles to the surface of it’s container

there is a force on the outside of the container due to pressure of gas around it

If a container can change it’s size than a change in these pressures will cause the container to compress or expand

Doing work on a gas…

increases internal energy, increases temperature

mechanically - bike pump

Explain how the pressure of a gas in a container is affected by temperature and number of particles.

• Gas particles move randomly and collide with the walls of the container.

• These collisions exert a force on the walls, creating pressure (force per unit area).

• Increasing temperature increases particle speed, which increases collision frequency and force.

• Adding more particles increases the number of collisions, also increasing pressure.

why pressure increases when temperature increases

particles would have a higher kinetic energy

(so) increased number of collisions with the walls of the balloon per second

greater forces exerted in collisions (between particles and balloon walls)

greater force exerted on same area

for all questions remeber

causing a higher/lower average force on walls

pressure is total force per unit area