Physics 5- The atom

Question 1

What does the Nucleus Contains

Answer 1

Protons / Neutrons

Question 2

What charge is the nucleus

Answer 2

Positive

Question 3

What comprises most of an atom

Answer 3

Empty space

Question 4

The radius of the atoms nucleus is about 10,000 times smaller than the radius of what?

Answer 4

The atom

Question 5

number of protons is equal to what?

Answer 5

number of electrons

Question 6

atomic number defines what?

mass number defines what?

Answer 6

protons

Question 7

When a nuclei decays, what 3 things will it split into?

What does this generally form?

Answer 7

Alpha
Beta
Gamma

A new element

Question 8

When atoms gain/lose electrons, what does this form?

What are the 3 types of ionising radiation?

Answer 8

ions

a, b , g

Question 9

Radiation from space is known as what?

Answer 9

Cosmic rays

Question 10

What is the highest background radiation proportion?

Answer 10

Radon gas

Question 11

Whats the lowest background radiation proportion coming from?

Answer 11

Nuclear industry

Question 12

An alpha particle consists of how many neutrons/protons?

therefore what is its mass/charge?

Answer 12

2 protons / 2 neutrons

mass of 4
Charge of 2+

Question 13

What are alpha particles good at (property)? why?

Answer 13

strong ionising

slow/heavy and bash into other atoms and creates ions

Question 14

how far can alpha particles travel?

Answer 14

few cm in air

Question 15

B particles are what?

name 2 properties from them that make them moderately ionising

Answer 15

electrons

fast / small

Question 16

whats the mass and charge of b-particles

Answer 16

0 mass

-1 charge

Question 17

Gamma rays are just what?

What does this mean for ionising?

Answer 17

EM waves

weak ionising - pass straight through atoms

Question 18

What material stops alpha?
what material stops beta
what material stops gamma

Answer 18

paper
aluminium
lead

Question 19

For every B-particle emitted from an element, what happens?

Answer 19

A neutron turns into a proton

atomic number increases with same mass number

Question 20

what happens when alpha + beta enter a magnetic/electric field?

Answer 20

both are deflected in opposite directions due to their charge

Question 21

which feels a greater force when entering a magnetic field… alpha or beta and why

Answer 21

Alpha as it has a greater mass

Question 22

What happens to GM when they enter an electric field

Answer 22

Nothing as they have no mass/charge

Question 23

Radiation dose is measured in?

Answer 23

sieverts (SV)

Question 24

underground rocks can release what?

Answer 24

Radon gas

Question 25

Why does high altitude (pilots) have increased chance of getting cancer?

Answer 25

Cosmic ray exposure

Question 26

Half life is what?

Answer 26

average time it takes for the number of unstable nuclei in a radioactive isotope sample to halve

Question 27

With half life equations, whats the first step to do?

Answer 27

Remove background radiation from the readings

Question 28

Whats the 2nd step in half life equations?

Answer 28

take intial count and keep dividing by 2 until you reach the figure you need

Question 29

whats the 3rd step in half life equations

Answer 29

divide the time (been given) by the amount of half lives you have calculated from 2nd step

Question 30

in smoke detectors, what type of radiation is present?

What does this mean for smoke + Alarm

Answer 30

alpha radiation

alpha causes ionisation = current
Smoke absorbs radiation = no current = alarm

Question 31

Name a type of radiation used as a tracer in medicine

Answer 31

iodine 131

Question 32

What type of radiation are used for anything involving the body? whats its half life need to be?

Why?

Answer 32

beta / gamma. short half life so disappears quickly

they can pass out of the body

Question 33

B-radiation can be used for what in industry?

Answer 33

Thickness gauges

passes through paper = if detector changes different level of radiation passing through, its too thick/too thin

Question 34

When uranium decays (Half life) what does it decay into?

Answer 34

uranium + lead

Question 35

Outside the body, what type of radiation is the most dangerous? why?

Answer 35

beta / gamma

can penetrate the skin –>organs

Question 36

Inside the body, what type of radiation is the most dangerous?

Answer 36

alpha is it is strong ionising and cant escape

Question 37

Whats used as protection when handling radiation?

Answer 37

lead as it absorbs all 3 type of radiation

Question 38

In nuclear power stations, what atoms split into to form?

What “fuel” are used?

Answer 38

heat –>steam from water –> steam turbine

Uranium 235 / plutonium 239

Question 39

for nuclear fission to work in a power station, what must starts the process? What does this lead to?

Answer 39

neutron is fired at the uranium 235 /plutonium 239

“fuel” becomes unstable–>breaks down into Barium + Krypton (Smaller nuclei) + 2 neutrons

Question 40

What can happen with the 2 neutrons released from the breakdown of the “fuel”?

What stops this?

Answer 40

chain reaction causing overheating due to too much fuel being broken down

Control rods absorb neutrons

Question 41

How can control rods stop meltdowns?

Answer 41

raised/lowered further into reaction to absorb more/less neutrons

this leads to less/more chain reactions from occuring

Question 42

How does nuclear fusion differ from fission?

What does it involve?

Answer 42

formation of He + energy

2H+ coming together at high temperature/pressure