Physics Paper 1 Summary

Describe the plum pudding model.

Atoms were spheres of positive charge with electrons stuck in them randomly

Describe Rutherford’s practical.

Fired alpha particles at thin gold foil, expecting them to pass straight through

What did Rutherford’s results show?

That most particles passed straight through, but some were deflected

What did Rutherford’s results demonstrate about the atom?

Atom had a small, positively charged nucleus in the centre but was mostly empty space

What the Bohr’s description of the atom?

Similar to Rutherford, but the electrons were fixed in electron shells

What is found in the electron shells?

Electrons

What charge do neutrons have?

Neutral

What charge do protons have?

Positive

What charge do electrons have?

Negative

What is the relative atomic mass of neutrons?

1

What is the relative atomic mass of protons?

1

If the atom gains electrons, what charge will it have?

Negative

If the atom loses electrons, what charge will it have?

Positive

What happens if an electron absorbs energy from EM radiation

It gets excited and can move up an energy cell

What happens when an atom emits EM radiation?

Electron falls back down an energy shell

What is an ion?

Atom that has lost an electron

What is ionising radiation?

Any radiation that can knock electrons from atoms

What is an isotope?

Atom with a different number of neutrons

What does the mass number show?

Number of protons + number of neutrons

What does atomic number show?

Number of protons

Which number is different in an isotope - mass or atomic?

Mass

What happens to unstable atoms?

Undergo radioactive decay

What is alpha radiation made up of?

2 protons and 2 neutrons

What can absorb alpha?

Skin/paper

Is alpha ionising?

Yes

What is beta+ radiation?

Positron

What is beta- radiation?

Electron

What is beta absorbed by?

Absorbed by aluminium

Is beta ionising?

Yes

What is gamma radiation made up of?

It is an EM wave

What can absorb gamma?

Thick lead

Is gamma ionising?

Yes

What happens to the mass number after alpha decay?

Mass number decreases by 4

What happens to the atomic number after alpha decay?

Decreases by 2

What happens to the mass number after beta+ decay?

Doesn’t change

What happens to the atomic number after beta+ decay?

Increases by 1

What happens to mass number after beta- decay?

Doesn’t change

What happens to the atomic number after beta- decay?

Increases by 1

What happens to the mass number after neutron emission?

Decreases by 1

What happens to the atomic number after neutron emission?

Doesn’t change

What happens to the mass number during gamma decay?

Doesn’t change

What happens to atomic number after gamma decay?

Doesn’t change

What is half life?

Time taken for the number of radioactive nuclei to halve

What is the activity of a source measured with?

Geiger-muller tube

What is activity measured in?

Becquerel’s (Bq)

What is irradiation?

Exposure to radiation but not radioactive

What is contamination?

Radiation gets into the body

Why is radiation dangerous?

Can damage DNA and then lead to cancer

What are the 2 types of waves?

Transverse and longitudinal

What do waves transfer?

Energy

What does amplitude mean?

Distance from the undisturbed position to the peak of a wave

What does crest mean?

Top of displacement

What does trough mean?

Bottom of displacement

What is frequency?

How many waves pass a fixed point in 1s

What is the period of a wave?

The number of seconds taken for 1 full cycle

How do transverse waves oscillate?

Perpendicular to the direction of travel

How do longitudinal waves oscillate?

Parallel to the direction of travel

What is frequency measured in?

Hertz (Hz)

What is wavelength measured in?

Metres (m)

What is wave speed measured in?

m/s

What is distance measured in?

Metres (m)

What is time measured in?

Seconds (s)

Give 3 transverse waves.

Radiowaves, microwaves, infrared

Give 2 longitudinal waves.

Sound waves, P waves

What 3 things can happen to waves at boundaries?

Absorbed, transmitted, or reflected

What is refraction?

When waves change direction at a boundary

Why does light change direction when entering a glass block at an angle?

Glass is more dense - light slows down

What is the normal?

Imaginary line perpendicular to where the wave hits the medium

What are the EM waves?

* Radiowaves
* Microwaves
* Infrared
* Visible light
* UV
* X-rays
* Gamma

Which EM wave has the highest frequency?

Gamma

Name a use for radiowaves?

Communication

Name a use for microwaves?

Cooking

Name a use for infrared.

Remote controls

Name a use for visible light.

Photography

Name a use for UV?

Tanning

Name a use for x-rays.

Medicine

Name a use for gamma.

Treating cancer

Name a danger for radiowaves.

None

Name a danger for microwaves.

Burn

Name a danger for infrared.

Burn

Name a danger for visible light.

Damage eyes at high intensity

Name a danger for UV.

Skin cancer

Name a danger for x-rays.

Cancer

Name a danger for gamma.

Cancer

How are radiowaves made?

Through oscillating charges in a circuit

Why can light disperse when hitting a boundary?

Colours of light travel at different wave speeds

What is the order of colours in visible light?

* Red
* Orange
* Yellow
* Green
* Blue
* Indigo
* Violet

List the energy stores.

* Kinetic
* Thermal
* Chemical
* Gravitational potential
* Elastic potential
* Electrostatic
* Magnetic
* Nuclear

What energy store is in moving objects?

Kinetic

Which energy store is released through nuclear reactions?

Nuclear

Which energy store is released through chemical reactions?

Chemical

Which energy store is in all objects - but hotter objects have more of it?

Thermal

What is energy measured in?

Joules (J)

What is mass measured in?

Kilograms (kg)

What is velocity measured in?

m/s

What is the gravitational field strength on Earth?

10 N/kg

What happens to the GPE as height increases?

Increases

What happens to GPE as an object falls?

Decreases

When an object hits the floor what happens to its KE?

Decreases

What does dissipate mean?

Transferred to the surroundings