Nuclear Chemistry

Marie Curie discovered that there was something going on inside the Uranium atom that created the rays, she named this effect “radioactivity”

Nuclear Symbols Mass number (p+ + no) Element symbol Atomic number (number of p+)

Radioactive Decay Radioactivity Nuclear Equation when a nucleus spontaneously decomposes, forming a different nucleus and producing one or more particles. Nuclear Equation Both the atomic number and the mass number must be conserved. That is the sums of both on each side must be equal.

Radioactive Particles Particle Type Symbol Mass Penetrating Power Alpha Particle 4 Low  Blocked by paper or clothing Beta Particle Moderate Blocked by metal foils Gamma Ray High Incomplete shielding by lead and concrete.

Types of Radioactive Decay Definition End Result Alpha-particle Production Decay of the nucleus of a large atom that results in the formation of an alpha particle Atomic mass reduced by 4 and atomic number is reduced by 2 Beta-particle Production The net effect of beta-particle production is to change a neutron to a proton. Releases a beta-particle. No change in mass number, but an increase in one of the atomic number Positron Production Positron has the same mass as an electron, but opposite charge. Not common. No change in mass. But a decrease in one of the atomic number. Electron Capture A process in which one of the inner-orbital electrons is captured by the nucleus Atomic number decreases by one, but the mass remains the same.

Gamma Rays Gamma rays are photons of electromagnetic radiation with high frequency and energy. Gamma rays are given off during other types of radioactive decay.

Half-life The time required for half of the original sample of nuclei to decay.

Half-life Concept

Decay Series A decay series will occur until a stable nuclide is formed.

Nuclear Fission The process of splitting an atom. http://www.teachersdomain.org/asset/phy03_vid_fission/ The process of splitting an atom. Releases an enormous amount of energy. 1 mol of uranium-238 can produce about 26 million times as much energy as 1 mol of methane.

Nuclear Fusion energy than fission. The process of combining two light nuclei. Produces more energy than fission. http://www.teachersdomain.org/asset/phy03_vid_fusiontest/

Effects of Radiation on Living Organisms Radiation may be absorbed by the medium it passes through. Radiation can kill living cells or change the nature of living cells.

Making Use of Radioactivity Humans have the ability to harness and manipulate radioactivity for: National defense and weaponry Medical diagnosis and treatments Energy production Radioactive Dating

Radiation Detection Approximate amounts of radiation can be detected by the following devices: Film badge Geiger-Muller counter Scintillation counter

Radiation Detection The film badge is worn on a lapel, the wrist, or finger, and detects the approximate accumulated dose of radiation over time. People who work with radiation, such as x-ray technicians, will wear such a device.

Radiation Detection The Geiger-Muller counter detects the approximate radiation present at any given time by counting electric pulses carried by gas ionized by radiation. The Geiger-Muller counter would be used to detect an approximate radiation dose that a person has been exposed to, such as when the Fukushima nuclear power plant leaked radiation.

Radiation Detection The scintillation counter can detect ionizing radiation. Some substances absorb. e The scintillation counter can detect ionizing radiation. Some substances absorb ionizing radiation and emit visible light, or scintillate. A scintillation counter would be used in border security, homeland security, and nuclear plant safety, among other things.