P5.2.2 & P5.2.3 & P5.2.4 - Nuclear Emission, Radioactive Decay & Half-life Flashcards
What are the 3 types of nuclear emission? [3]
- alpha
- beta
- gamma
Describe the nature of alpha particles. [2]
- consist of 2 protons and 2 neutrons
- a helium nucleus
Describe the nature of beta particles. [1]
- fast moving electrons emitted from the nucleus
Describe the nature of gamma rays. [1]
- they are electromagnetic waves
Describe the ionising effect of alpha radiation. [1]
strong ionising effect
Describe the ionising effect of beta radiation. [1]
moderate ionising effect
Describe the ionising effect of gamma radiation. [1]
weak ionising effect
Describe the penetrating ability of alpha radiation. [2]
- low penetrating ability
- can be stopped by paper or skin
Describe the penetrating ability of beta radiation. [2]
- moderate penetrating ability
- can be stopped by a sheet of plastic or glass
Describe the penetrating ability of gamma radiation. [3]
- high penetrating ability
- can pass through most materials
- can be stopped by thick lead or concrete
What does ionising effect mean? [1]
when radiation gives energy to atoms causing them to change or break apart.
What does penetrating ability mean? [1]
how far radiation can go through materials
Which radiation is the fastest moving? [1]
gamma
Which radiation is the slowest moving? [1]
alpha
What is radioactive decay? [2]
- the process in which an unstable nucleus gives out radiation to become more stable
- the changes are spontaneous and random
What happens to the nucleus of an atom during alpha decay? [2]
- the atom releases 2 protons and 2 neutrons
- changes the atom into a new element since it loses 2 protons
What happens to the nucleus of an atom during beta decay? [2]
- a neutron turns into a proton and and an electron is released
- this changes the atom into a new element because it gains a proton
What is the change that happens in the nucleus during Beta decay? [3]
- neutron changes into a proton and an electron
- the proton stays in the nucleus but the electron is pushed out
- this makes the atom change into a new element because the number of protons has increased
What is the formula process of what happens during beta decay? [1]
neutron —> proton + electron
What is the decay equation for alpha? [2]
ᴬ ⁴ ᴬ⁻⁴
X —> He + (element)
ᶻ ₂ ᶻ₋₂
What is the decay equation for beta? [2]
¹⁴ ¹⁴ ⁰
C —-> N + e
₆ ₇ ₋₁
What is the decay equation for gamma? [2]
ᴬ ⁰ ᴬ
X —> Y + X
ᶻ ₀ ᶻ
What is half-life? [2]
the time taken for half the nuclei of that isotope in any sample to deca
What is the graph like for half life? [1]
exponential decrease
