Chapter 2: Nuclear Transformations Flashcards
What is the equation for radioactive decay?
What do the variables mean?
𝑁=𝑁(0)𝑒^(−𝜆𝑡)
N - number of atoms at a given time
N0 - number of atoms at start
𝜆 - decay constant
t - time
What is the activity of a radioactive material?
Defined at the number of disintigrations per unit time
What is the equation for Activity change with time?
What do the variables mean?
A=A(0)𝑒^(−𝜆𝑡)
A - activity at a given time
A0 - activity at the start
𝜆 - the decay constant
T - time
What is a curie (Ci)?
1 Ci = 3.7 x 10^10 Bq
What is a Becquerel (Bq)?
A unit of activity indicating 1 disintegration per second
How many Bq are in 1 mCi?
3.7 x 10^7 Bq
What is the equation for calculating half life of an isotope?
T1/2 = Ln(2)/ 𝜆
What is Ln(2)
0.693
What is the mean/ average life and how is it calculated?
The lifetime of a radioactive atom before it decays fully
Ta = 1.44*T1/2
Secular Equilibrium
When the parent half life is significantly longer than the daughter half life
Transient Equilibium
when the half life of the parent is not much longer than the daughter
What is alpha particle decay?
The ejection of a helium nucleus (no electrons)
226 Ra –> 222 Rn + 4He = 4.76 MeV
What type of decay is this?
Alpha decay
B (-) decay
The transformation of a neutron into a proton with ejection of an electron and an anti-neutrino
B (+) decay
The transformation of a proton into a neutron and a positron and a neutrino
