Ch. 9 Atomic and Nuclear Phenomena formulas Flashcards
1
Q
energy of a photon of light
A
E= hf
2
Q
Kmax of an electron in photoelectric effect
A
Kmax = hf - W
3
Q
Work function
A
W= hfT
4
Q
Mass defect and energy
A
E= mc^2
5
Q
Alpha decay
A
lose 2 protons and 2 neutrons + ejection of alpha particle
6
Q
beta - decay
A
neutron turns into proton
net gain of one proton
7
Q
beta positive decay ( positron emission)
A
proton turns into neutron
net loss of one proton in atomic number
atomic mass stays the same
8
Q
Gamma decay
A
emission of gamma particle
atomic mass and atomic number seemingly unchanged
9
Q
Electron capture
A
net loss of 1 proton
10
Q
rate of nuclear decay
A
delta n / delta t = - lambda * n
11
Q
Exponential decay
A
n= n0 * e^ - lambda *t
12
Q
decay constant ( lambda)
A
ln2/T(.5) =
ln2 -= .693
