Radioactivity

Uses of Radioisotope in Industry Monitoring Content of Food Monitoring Thickness of Steel/paper Sheet Detecting Underground Leakage Measuring the Wearing Rate of Engine

  In archaeology radioisotope carbon-14 is used to study and estimate the age of ancient artifacts. This method is named as the radiocarbon dating. Radiocarbon dating can be used to estimate the age of organic materials, such as wood and leather, up to about 58,000 to 62,000 years.     Example:A piece of wood found … Read more

Half-life The half-life ( T½ ) of a quantity subject to exponential decay is the time required for the quantity (mass, number of atom or activity) to decay to half of its initial value.  The decay curve of a radioactive source can be found experimentally – provided the activity of the source decreases over a … Read more

Gamma Emission  Gamma emission causes no change in nucleon number or proton number.

Beta Decay A beta particle is an electron emitted from a nucleus. The beta particles are very small and move with very high speed. During beta decay, a radioactive atom X decay and emits a beta particle ( 0-1e). One of the neutron is disintegrated to become proton and electron. The electron is emitted out … Read more

Alpha Decay During alpha decay, a radioactive atom X decay and emits an alpha particle ( 42He). Atom X losses 2 neutron and 2 protons and become atom Y. Example

Film Badge (Dosimeter) Film badge dosimeters are small portable devices used to monitor cumulative radiation dose due to ionizing radiation. The device consists of two parts: photographic film and a holder. The film emulsion is black and white photographic film with varying grain size to affect its sensitivity to incident radiation. The ionisation effect by … Read more

Spark-Chamber Detector [Can detect: Alpha particles only] A spark-chamber detector is a particle detector, that is, a device used in particle physics for detecting electrically charged particles.  Spark-chamber detectors consists of metal plates placed in a sealed box filled with gas (for example, helium, neon or a mixture of the two); as a particle travels … Read more

Cloud Chamber [Can detect: Alpha, Beta and Gamma] Figure above shows a simple form of cloud chamber, a device which enables the tracks of charged particles to be seen.  The felt ring round the top of the chamber is soaked in alcohol. The bottom of the chamber is cooled by ‘dry ice’ (solid carbon dioxide) … Read more

Geiger-Muller Tube [Can detect: Alpha, Beta and Gamma] The tube contains argon gas at low pressure. The end of the tube is sealed by a mica ‘window’ thin enough to allow alpha particles to pass into the tube as well as beta and gamma radiation. When a charged particle or gamma-radiation enters the tube, the … Read more