Transcript Nuclear Chemistry

Inorganic Chemistry May 12, 2015
Describe how the strong force attracts nucleons
Relate binding energy and mass defect
Predict the stability of a nucleus by considering
factors such as nuclear size, binding energy, and
the ratio of neutrons to protons in the nucleus
Nucleons and nuclide
Protons and neutrons are nucleons
A specific number of protons and neutrons are
described as a nuclide
An isotope has the same atomic number but
different mass number
Isotopic notation
Mass #
25
Mg
Atomic #
12
Chemical Symbol
Strong force exists when nucleons are close
together
The strong force must overcome the electrical
charge of the protons
Three quarks make up nucleons
Quarks are in flavors
Binding energy and Mass Defect
separate nucleons  nucleus + energy
Nuclear binding energy is the energy associated
with the loss of mass, mass defect, from the
combining of nucleons
Eo = mc2
4 He
2.73 x 10 12
J/mol
2
1. Except for 11H and 32He, all stable nuclei have
a number of neutrons that is equal to or greater
than the number of protons
A nucleus that has an N/Z number that is too
large or too small is unstable. Gradual increase
from 1 to 1.5
Nuclei with even number of neutrons and
protons are more stable
Nuclei that have magic numbers of protons and
neutrons [2,8,20,28,82,&126]
1-12 Skip 2’s page 647
1-9 Skip 2’s page 874
Mass of a proton 1.672614 x 10-27 kg
Mass of a neutron 1.6749543 x 10-27 kg
Speed of light 3.00 x 108 m/s