Nuclear Chemistry
The study of reactions that take place in the nucleii of atoms Nuclear Chemistry The study of reactions that take place in the nucleii of atoms
In normal chemical reactions, only the electrons are involved
A nucleus that spontaneously decomposes Radioactive Nucleii A nucleus that spontaneously decomposes
Elements with the same atomic number, but different mass number Isotopes Elements with the same atomic number, but different mass number
Elements with = numbers of protons, but numbers of neutrons Isotopes Elements with = numbers of protons, but numbers of neutrons
All elements have at least one radioactive isotope Isotopes All elements have at least one radioactive isotope
Radiation The emission of particles & rays from spontaneously decomposing nucleii
Modes of Decay Alpha emission Beta emission Gamma emission Positron emission K-electron capture
Name five types of radiation Drill: Name five types of radiation
Penetration power: small Alpha Particle (a) Helium nucleus 2 protons & 2 neutrons mass = 4 amu charge = +2 Penetration power: small
Penetration power: medium Beta Particle (b) High speed electron 1 electron mass = 1/1836 amu charge = -1 Penetration power: medium
Penetration power: great Gamma Ray (g) High energy photon Electromagnetic wave mass = 0 charge = 0 Penetration power: great
Penetration power: medium Positron (p) Positive electron 1 positive electron mass = 1/1836 amu charge = +1 Penetration power: medium
The capture of an inner level e- by the nucleus K-capture The capture of an inner level e- by the nucleus 1 electron mass = 1/1836 amu charge = -1
Nuclear Symbol Alpha: 24He or 24a Beta: -10e or –10b Gamma: 0 0 Positron: +10e K-electron: -10e
Fission The splitting of a nucleus into smaller nucleii involving the release of energy
Fusion The combining of smaller nuclei into a larger one involving the release of energy
Nuclear reactions in which one element is changed into another Transmutation Rxns Nuclear reactions in which one element is changed into another
Reactions in which the nucleus of an atom is changed Transmutation Rxns Reactions in which the nucleus of an atom is changed
Both fission & fusion are examples of transmutation rxns
Can occur through emission of or bombardment by radioactive particles Transmutation Rxns Can occur through emission of or bombardment by radioactive particles
Transmutation Rxns b emission of Pm-142 a emission of U-238 K-capture by O-15 p addition of O-18
a emission of U-238 followed by two separate b emissions: Transmutation Rxns a emission of U-238 followed by two separate b emissions:
a bombardment of Th-234 followed by two separate b emission: Transmutation Rxns a bombardment of Th-234 followed by two separate b emission:
a Neutron absorption by U-238 followed by two separate b emission: Predict Products a Neutron absorption by U-238 followed by two separate b emission:
a emission of O-18 followed by a Predict Products a emission of O-18 followed by a b emission:
K-capture by V-45 followed by neutron emission then a emission Predict Products K-capture by V-45 followed by neutron emission then a emission
The rate at which a radioactive nucleus breaks down Decay Rate The rate at which a radioactive nucleus breaks down
The time it takes for 50 % of the radioactive nucleii to decompose Half-Life The time it takes for 50 % of the radioactive nucleii to decompose
Decay Rate Rate = kdX/dt ln(Xo/X) = kt1/2 k = 0.693/t1/2 t1/2 = half-life
Drill: Predict the products in each step when B-12 goes through a bombardment followed by b emission.
1st Order Age Dating Formula t = ln(Xi/Xf)t1/2 0.693
Calculate the age of a skeleton found with 0 Calculate the age of a skeleton found with 0.125 % C-14 when atmospheric C-14 = 1.00 %. t1/2 C-14 = 5720 yr
Calculate the age of a tooth found with 0 Calculate the age of a tooth found with 0.00132 % C-14 when atmospheric C-14 = 1.00 %. t1/2 C-14 = 5720
Calculate the age of a bone found with 0 Calculate the age of a bone found with 0.000300 % C-14 when atmospheric C-14 = 1.00 %. t1/2 C-14 = 5720
Mass-Energy Relations DE = Dmc2
Nuclear Fact The mass of any nuclei is different than the sum of the masses of its protons & neutrons
The energy corresponding to the mass difference can be solved using: Nuclear Fact The energy corresponding to the mass difference can be solved using: DE = Dmc2
Binding Energy The energy that holds a nucleus together which corresponds to Dm of nucleus
In an atomic bomb, 40. 00 kg of U-235 (235 In an atomic bomb, 40.00 kg of U-235 (235.401) is split into Ba-144 (14 3.223) + Kr-89 (89.335) + 2 neutrons (1.014). A) Calculate the energy released. B) Calculate the wavelength of the g ray
Show neutron bombardment of Ra-223 followed by 3 alpha emissions