Chapter 3 + 4 - Nuclear Chemistry

nuclear chemistry

nuclear chemistry

sub-field of chemistry dealing with radioactivity, nuclear processes, and transformations in the nuclei of atoms, such as nuclear transmutation and nuclear properties.

nuclear reactions

In a nuclear decay reaction, also called radioactive decay, an unstable nucleus emits radiation and is transformed into the nucleus of one or more other elements.

alpha particles

also called alpha rays or alpha radiation, generally produced in the process of alpha decay, but may also be produced in other ways. consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus.

beta particles

also called beta ray or beta radiation, is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay. two forms of beta decay, β⁻ decay and β⁺ decay, which produce electrons and positrons respectively.

gamma particles

also known as gamma radiation. penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays.

stability of an atomic nucleus

Nuclear stability means that the nucleus of an element is stable and thus it does not decay spontaneously emitting any kind of radioactivity

radioactive elements

A radionuclide is a nuclide that has excess nuclear energy, making it unstable. most radioactive elements are: uranium; plutonium-239; plutonium-238; cesium-137; strontium-90.

calculating the number of neutrons and protons of isotopes

Calculating the number of neutrons then becomes atomic mass of the isotope minus the atomic number of the element equals the number of neutrons. For uranium-235, atomic number 92, the number of neutrons is 235-92=143, or 143 neutrons.

nuclear equations alpha decay

The reaction can be represented by this nuclear equation:

92 238 U → 90 234 T h + 2 4 H e + Energy.

nuclear equations beta decay

This reaction is represented by the equation:

90 234 T h → 91 234 P a + − 1 0 e + energy

half life

the time taken for the radioactivity of a specified isotope to fall to half its original value or the time required for any specified property to decrease by half.

ex: iodine-131 has a half-life of 8.1 days

nuclear fission

a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy.

nuclear fusion

a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.

isotope notation

Method to define the characteristics for an isotope for an element.

ex: C-14 (carbon-14)