Nuclear Chemistry Flashcards
1
Q
alpha decay
A
- emission of an alpha particle consisting of 2 protons and 2 neutrons
- helium nucleus
- A = 4
- Z = 2
2
Q
beta decay
A
- emission of an electron from the nucleus
- A = 0
- Z = 1
3
Q
gamma decay
A
- emissions of gamma particles which are high energy photons
- A = 0
- Z = 0
4
Q
positron emission
A
- emission of a positron from the nucleus
- A = 0
- Z = +1
5
Q
fraction of nuclei remaining after n half lives
A
(1/2)^n
6
Q
fraction of nuclei that has decayed after n half lives
A
1 - (1/2)^n
7
Q
binding energy
A
- negative energy of the electron bound to the nucleus
- mass defect
- BE = (deltam)c^2
- the difference between the sum of the masses of the individual nucleons and the mass of the nucleus
8
Q
values of energies at different levels n given in electron-volts
A
En = 13.6eV/(n^2)
9
Q
radiation and absorption of light are caused by
A
transition of atomic electrons from one energy state to another
10
Q
electrons jump form one energy state to another
A
- must make discrete jumps
- must absorb or emit a photon of equal energy
11
Q
energy of a photon
A
E = hf
- photon emission (E < 0)
- photon absorption (E > 0)
12
Q
nuclear half life
A
- population of radioactive nuclei will decay at an exponential rate
- N = N0e^-tlamda
13
Q
half life
A
T1/2 = .693/lamda
