Drill: Calculate the solubility of MgF 2 in 0.10 M KF. K sp MgF 2 = 6.4 x 10 -9

Drill: Calculate the volume of Cl 2 formed at 27 o C under 75 kPa when xs molten NaCl is electrolyzed with 96.5 mA for 5.0 mins.

Nuclear Chemistry

The study of reactions that take place in the nuclei of atoms

Chemical Reactions In normal chemical reactions, only the electrons are involved

Radioactive Nuclei Nuclei that spontaneously decompose

Isotopes Elements with the same atomic number, but different mass number

Isotopes Elements with = numbers of protons, but  numbers of neutrons

Isotopes All elements have at least one radioactive isotope

Radiation The emission of particles & rays from spontaneously decomposing nuclei

Modes of Decay Alpha emission Beta emission Gamma emission Positron emission K-electron capture

Alpha Particle (  ) Helium nucleus 2 protons & 2 neutrons mass = 4 amu charge = +2 Penetration power: small

Beta Particle (  ) High speed electron 1 electron mass = 1/1836 amu charge = -1 Penetration power: medium

Gamma Ray (  ) High energy photon Electromagnetic wave mass = 0 charge = 0 Penetration power: great

Positron (  ) Positive electron 1 positive electron mass = 1/1836 amu charge = +1 Penetration power: medium

K-capture The capture of an inner level e - by the nucleus 1 electron mass = 1/1836 amu charge = -1

Nuclear Symbol Alpha: 2 4 He or 2 4  Beta: -1 0 e or –1 0  Gamma: 0 0  Positron: +1 0 e K-electron: -1 0 e

AP CHM HW Read: Chapter 19 Problems: 5 & 7 Page: 552

CHM II HW Read: Chapter 26 Problems: 31 & 35 Page: 1036

Fission The splitting of a nucleus into smaller nuclei involving the release of energy

Drill: Name five types of radiation

Drill: Name 3 common types of radiation

Fusion The combining of smaller nuclei into a larger one involving the release of energy

Transmutation Rxns Nuclear reactions in which one element is changed into another

Transmutation Rxns Reactions in which the nucleus of an atom is changed

Transmutation Rxns Both fission & fusion are examples of transmutation rxns

Transmutation Rxns Can occur through emission of or bombardment by radioactive particles

Transmutation Rxns  emission of Pm-142  bombardment of Th-231

Transmutation Rxns  emission of  U   followed by two separate  emissions:

Transmutation Rxns  bombardment of Th  followed by two separate  emission:

Drill: Predict Prod Neutron absorption by U  followed by two separate  emission:

Drill: Predict Products  emission of O-18 followed by a  emission:

Predict Products K-capture by V-45 followed by neutron emission then  emission

Predict Products  absorption by V- 45 followed by neutron emission then  emission

Decay Rate The rate at which radioactive nuclei break down

Half-Life The time it takes for 50 % of the radioactive nuclei to decompose

Decay Rate Rate = k  X/  t ln(X i /X f ) = kt 1/2 k = 0.693/t 1/2 t 1/2 = half-life

Drill: Predict the products in each step when Boron-12 goes through  bombardment followed by  emission.

1st Order Age Dating Formula ln(X i /X f )t 1/ t =

Calculate the age of a skeleton found with % C-14 when atmospheric C-14 = 1.00 %. t 1/2 C-14 = 5720 yr

Calculate the age of a tooth found with % C-14 when atmospheric C-14 = 1.00 %. t 1/2 C-14 = 5720

AP CHM HW Read: Chapter 19 Problems: 26 & 27 Page: 553

CHM II HW Read: Chapter 26 Problems: 53 & 54 Page: 1037

Calculate the age of a bone found with % C-14 when atmospheric C- 14 = 1.00 %. t 1/2 C-14 = 5720

Drill: A fossil contained 3.125% of its original carbon-14. Determine its age. t 1/2 for C-14 = 5720 yrs

Mass-Energy Relations  E =  mc 2

Nuclear Fact The mass of any nucleus is different than the sum of the masses of its protons & neutrons

Nuclear Fact The energy corresponding to the mass difference can be solved using:  E =  mc 2

Binding Energy The energy that holds a nucleus together corresponds to  m of nucleus

In an atomic bomb, kg of U-235 ( ) is split into Ba-143 ( ) + Kr-89 (89.335) + 2 neutrons (1.014). A) Calculate the energy released. B) Calculate the wavelength of the  ray

Drill: Show neutron bombardment of Ra-223 followed by 3 alpha emissions

Drill: Show the intermediates and the final isotope of alpha bombardment of Xe-136 followed by two separate beta emissions.