Intro Chem Chapter 9 Study Notes

Nuclear Radiation

Radiation emitted from a nucleus during decay.

Alpha Particle (α)

Helium nucleus; mass 4 amu; atomic number 2.

Beta Particle (β-)

An electron with a mass of 0.00055 amu.

Positron (β+)

Similar mass to an electron (0.00055 amu) but with a +1 charge.

Gamma Ray (γ)

High-energy electromagnetic radiation.

Natural Isotopes

Over 300 naturally occurring isotopes; 264 are stable; rest are radioactive.

Artificial Isotopes

Over 1000 artificial isotopes exist; all are radioactive.

Beta Emission

Process where a neutron converts to a proton and an electron, emitting the electron.

Alpha Emission

Emission of a helium nucleus, leading to a decrease in atomic number by 2 and mass number by 4.

Positron Emission

Emission of a positron from the nucleus; atomic number decreases by 1.

Gamma Emission

No change in atomic/mass number; high-energy state returns to ground state.

Electron Capture

An electron captured by a nucleus replaces a proton, forming a neutron.

Half-Life

Time taken for half the sample of a radioisotope to decay.

Radiation Dosimetry

Measurement of absorbed doses of radiation using units such as Becquerel (Bq) and Sievert (Sv).

Nuclear Medicine

Application of nuclear chemistry principles in medical treatments and diagnostics.

Nuclear Fusion

Combining of hydrogen nuclei to form helium, releasing energy as photons.

Nuclear Fission

Splitting of larger nuclei into smaller ones, initiating significant energy release.

Health Effects of Radiation

Varies from 25 rem (decreased white blood cells) to 600 rem (highly lethal).

Alpha Particle (α)

A helium nucleus consisting of 2 protons and 2 neutrons; mass: 4 amu.

Beta Particle (β-)

An electron with a charge of -1; mass: 0.00055 amu.

Positron (β+)

Similar mass to an electron (0.00055 amu) but with a +1 charge.

Gamma Ray (γ)

High-energy electromagnetic radiation.

Half-Life

The time taken for half the sample of a radioisotope to decay.

Beta Emission

A process where a neutron converts to a proton and emits a beta particle (electron), increasing atomic number by one.

Alpha Emission

The emission of a helium nucleus, reducing the atomic number by 2 and the mass by 4.

Radiation Dosimetry

Measurement of radiation exposure, using units like Becquerel (Bq) and Gray (Gy).

Nuclear Fusion

The process of combining hydrogen nuclei to form helium, releasing energy as photons.

Nuclear Fission

The splitting of larger nuclei into smaller ones, releasing significant energy.

Stability of Isotopes

Stable isotopes have similar numbers of protons and neutrons, while heavier elements require more neutrons.

Scintillation Counters

Instruments that emit light when struck by radiation, used for measuring radiation intensity.

Electron Capture

An electron is captured by a nucleus, replacing a proton with a neutron; atomic number decreases.

Roentgen (R)

A measure of ionizing energy delivered from a source; 1 R = 2.58 x 10⁻⁴ coulomb/kg.

Radiation Effects

Exposure levels have varying health effects; for example, 600 rem is almost invariably lethal within a month.