low energy higher energy than α → HIGHEST energy of all
☑ number of ptn ALPHA {α (plan) BETA.,B
↗ or i B r GAMMA 8
A Mass no. • can be stopped by Beta- or Betat • high energy EM wave
a few mm of paper • stopped by several • reduced by lead
Z
atomic no. • nucleus decays to cm of aluminium to unstable nucleus
number of protons smaller, more stable • a neutron decays into releases some energy
nucleus releasing fast a proton in form of gamma
more ionising moving HELIUM NUCLEI. • releases fast moving
photon.
- low penetration electron Low ionising
less penetrating - highly ionising e.g:c → IN +9, β highly penetrative
used in smoke detectors + Ip used as a medical
Radioactivity 92,38, → {In ÷ so neutron turns into proton tracer/radiotherapy
medium penetrating can cause cancer by
random-process medium ionising can also be used to
target cancer cells
A = Activity (Bq) = rate of decay of a sample of radioactive nuclei.
Ao = initial activity
2 = decay constant
Ty, = half life = time taken for number of radioactive nuclei
to reduce to one half of initial value.
N: Noé" or A- Aoent
A: Ag or N= N2; → A αi. A N= 2N
2= (Tn(½2) if Ty, = time taken for
exponential graph so = number activity to half
of nuclear decay of half lives
t = T'/2, No = ½ or 10 = £
N- Noett
N = eat
No
1=5212 take logs
(n(½) - Intent's)
in (1/2) = -2T'/2
2in (1/2) = The
2 = TI = (n (2)
in (1/2) T½
☑ number of ptn ALPHA {α (plan) BETA.,B
↗ or i B r GAMMA 8
A Mass no. • can be stopped by Beta- or Betat • high energy EM wave
a few mm of paper • stopped by several • reduced by lead
Z
atomic no. • nucleus decays to cm of aluminium to unstable nucleus
number of protons smaller, more stable • a neutron decays into releases some energy
nucleus releasing fast a proton in form of gamma
more ionising moving HELIUM NUCLEI. • releases fast moving
photon.
- low penetration electron Low ionising
less penetrating - highly ionising e.g:c → IN +9, β highly penetrative
used in smoke detectors + Ip used as a medical
Radioactivity 92,38, → {In ÷ so neutron turns into proton tracer/radiotherapy
medium penetrating can cause cancer by
random-process medium ionising can also be used to
target cancer cells
A = Activity (Bq) = rate of decay of a sample of radioactive nuclei.
Ao = initial activity
2 = decay constant
Ty, = half life = time taken for number of radioactive nuclei
to reduce to one half of initial value.
N: Noé" or A- Aoent
A: Ag or N= N2; → A αi. A N= 2N
2= (Tn(½2) if Ty, = time taken for
exponential graph so = number activity to half
of nuclear decay of half lives
t = T'/2, No = ½ or 10 = £
N- Noett
N = eat
No
1=5212 take logs
(n(½) - Intent's)
in (1/2) = -2T'/2
2in (1/2) = The
2 = TI = (n (2)
in (1/2) T½
