CHE 121: Chapter 11 (Nuclear Chemistry)

Published by admin on

Nucleon
A general term for both protons and neutrons.
Nuclide
The nucleus of a specific isotope of an element.
Nuclear Reaction
A reaction that changes an atomic nucleus, usually causing the change of one element into another.
Radioactivity
The spontaneous emission of radiation from a nucleus.
Gamma Radiation (symbol?)
γ
Alpha Particle (symbol?)
α
Beta Particle (symbol?)
β
Gamma (γ) Radiation
Radioactivity consisting of high-energy light waves.
Beta (β) Particle
An electron (e⁻), emitted as radiation.
Alpha (α) Particle
A helium nucleus (He²⁺), emitted as a “α” radiation.
Radioisotope
A radioactive isotope.
Radionuclide
The nucleus of a radioactive isotope.
Nuclear Decay
The spontaneous emission of a particle from an unstable nucleus.
Transmutation
The change of one element into another due to nuclear decay.
Alpha Emission
When an atom emits an “α” particle, the nucleus loses two protons and two neutrons.
Beta Emission
Involves the decomposition of a neutron to yield an electron and a proton.
Gamma Emission
Cause no change in the mass or atomic number because the rays are simply high-energy electromagnetic waves.
Gamma Emission
Can occur alone but usually accompanies “α” or “β⁻” emission as a mechanism for the new nucleus.
Positron (β+)
A “positive electron,” which has the same mass as an electron but a positive charge.
Symbol for Positron Emission
β+
Positron Emission
Conversion of a proton in the nucleus into a neutron plus an ejected positron.
Electron Capture (E.C.)
A process in which the nucleus captures an inner-shell electron from the surrounding electron cloud, thereby converting a proton into a neutron.
How many kinds of Radioactive Decay?
5
What are the kinds of Radioactive decay?
1. Alpha Emission; 2. Beta Emission; 3. Gamma Emission; 4. Positron Emission; 5. Electron Capture.
Symbol for Electron Capture
E.C.
Formula for Half-Life
(t1/2)
Half-life
The amount of time required for one-half of a radioactive sample to decay.
Decay Series
A sequential series of nuclear disintegrations leading from a heavy radioisotope to a non-radioactive product.
Ionizing Radiation
A general name for high-energy radiation of all kinds.
X Rays
Electromagnetic radiation with an energy somewhat less than that of Gamma Rays
Cosmic Rays
A mixture of high-energy particles- primarily of protons & various atomic nuclei- that shower the earth from outer space.
Artificial Transmutation
The change of one atom into another brought about by the nuclear bombardment reaction.
Critical Mass
The minimum amount of radioactive material needed to sustain a nuclear chain reaction.
Chain Reaction
The reaction is self sustaining
Nuclear Fission
The fragmenting of heavy nuclei
Nuclear Fusion
The joining together of light nuclei. Requires enormous amounts of “T” and pressure to take place.
Categories: Nuclear Chemistry