Unit 3.5 Nuclear Decay (involves gambling)

Question 1

Nucleon formula???
(Describing the nucleus)
(Or actually, element layout)

Answer 1

A = Z + N

^AX_Z

Question 2

Define A
(Describing the nucleus)
(2 things)

Answer 2

• Mass number
• N° of protons and neutrons in atom

Question 3

Define Z
(Describing the nucleus)
(2 things)

Answer 3

• Atomic number
• N° of protons in atom

Question 4

Define X
(Describing the nucleus)
(3 things)

Answer 4

• Atomic symbol
• Abbreviation used to represent
• atom in chemical formulas

Question 5

Proton number = ?
(Describing the nucleus)

Answer 5

Same number of electrons

Question 6

Define radioactivity?
(3-way)

Answer 6

• Spontaneous disintegration
• of an unstable nucleus
• within an atom

Question 7

Define radioactive emission?
(3-way)

Answer 7

• An attempt by the unstable nucleus
• to become more stable
• by emitting 3 types of radiation

Question 8

What are the 3 types of radiation emitted during radioactive emission?

Answer 8

• Alpha
• Beta
• Gamma

Question 9

What are the 2 things that stability/instability of the nucleus depend on?

Answer 9

• N° of nucleons
• Ratio of protons to neutrons

Question 10

Skipped page 4…. probably not needed?

Answer 10

I’ll come back one day… or not?

Question 11

What do they use to measure radiation?

Answer 11

A Geiger counter

Question 12

How do Geiger counters’ work?
(4-way)

Answer 12

• Principle of incoming radiation ionising a gas
• by knocking out an electron
• from electron shell
• to create both negative + positive ion pair

Question 13

How do u correct for background radiation?
(2-way)

Answer 13

• Subtracting the background count rate
• from the measured count rate

Question 14

Correcting for background radiation expressed as a formula?

Answer 14

(Corrected Count rate) = [Measured Count rate] - [Background]

Question 15

Describe the process of ionization?
(2-way)

Answer 15

• Addition/removal of an electron
• to gain an ion

Question 16

How do them ionization cloud chambers work?
(Fix-up)

Answer 16

• Dry ice needed to crate a ‘supersaturated’ environment
• Cools the alcohol vapour
• Radiation ionizes the vapour - condensing the alcohol along the radiation paths

Question 17

Why do beta particles produce poorly defined curved tracks?
(Ionisation within “cloud chamber”)
(2 things)

Answer 17

• Less ionizing
• Curved due to less mass

Question 18

Why do alpha particles produce well-define, thick straight tracks?
(Ionisation within “cloud chamber”)
(2 things)

Answer 18

• More ionizing
• Has more mass

Question 19

Why do gamma rays leave virtually no trail?
(Ionisation within “cloud chamber”)

Answer 19

Very low ionizing ability

Question 20

What stops alpha?

Answer 20

Tissue/cm of air

Question 21

What stops beta?

Answer 21

mms of aluminium

Question 22

What stops gamma?

Answer 22

Metres of concrete/cm’s of lead

Question 23

How can an electric field be used to classify the different types of radiation?
(2-way + 2 things)

Answer 23

• Beta = negative electron ∴ positive attract
• Alpha = positive ∴ goes to negative
• Alpha also heavier ∴ deflection = less
• Gamma = no charge ∴ no deflection

Question 24

Describe each finger for Fleming’s hand rule?
(3 fingers)

Answer 24

Thumb = motion
Index = magnetic field
Middle = current flow direction

Question 25

Which hand do u use alpha on?

Answer 25

Left hand

Question 26

Which hand do u use beta on?

Answer 26

Right hand

Question 27

How can a magnetic field be used to classify the different types of radioactive emission?
(3 separations)

Answer 27

• Alpha rays = slightly deflected in 1 direction
• Beta rays = deflected strongly in opposite direction
• Gamma rays = not deflected

Question 28

Describe alpha decay?
(4 things)

Answer 28

• Helium atom
  +
• -4 on mass number
• -2 on atomic number

Question 29

Describe beta decay?
(3 things & 2 +’s)

Answer 29

• Beta (-1 atomic number)
  +
• +1 on atomic number
  +
• V?

Question 30

Describe beta⁺ decay?
(3 things? & 2 +’s)

Answer 30

• Beta⁺ (+1 atomic number)
  +
• -1 on atomic number
  +
• V?

Question 31

Describe radioactive decay?
(2 things + 2-way)

Answer 31

• Spontaneous, no trigger to cause it
• Random occurrence
• Impossible to predict
• when individual nucleus will disintegrate

Question 32

What is activity (A) of a sample defined as?

Answer 32

N° of disintegrations per unit time

Question 33

What is the unit of activity?

Answer 33

Becquerel
(Bq)

Question 34

1 Bq = ?

Answer 34

1 disintegration each second

Question 35

What is decay constant generally?
(More needed, i hate logs)

Answer 35

Rate of change

Question 36

A crazy gamble, Will finish later, HOWEVER, the next part is literally just logs

Answer 36

Is this gonna be a good gamble?
or ask for help before it terrorizes

Question 37

So, i’m gonna gamble here only so i can save time, tho, might not be the best decision….

Answer 37

Don’t state here logs, i shall learn that separately on the whiteboard…. assuming i do that, ppq in addition to that. Shall truly be the crutch here (╯˘ -˘ )╯

Question 38

Define mole
(3-way)

Answer 38

• The amount of substance that contains…
• the same n° of particles
• as there is in 12g of Carbon-12

Question 39

So u know Avagadro’s constant N_A, what about that?
(2 things?)

Answer 39

• One mole of any substance
• contains N_A particles which is 6.02 x 10²³

Question 40

How do u find the molar mass of C or U?
(Of carbon or uranium)

Answer 40

You just…. look at the n° above…. “not the atomic number”

Question 41

Formula for number of moles?

Answer 41

N° of moles = Mass of sample/Mass of 1 mole
n = M/M_molar

Question 42

Formula for number of particles?
(BIG DIFFERENCE)

Answer 42

N° of particles = Mass of sample/Mass of 1 particle
N = M/m

Question 43

Once again, rlly bad last minute revision again. Surprisingly capacitance its like the knowledge retained at the back of my brain.

Answer 43

Just follow the plan.