The following radioactive elements are found naturally in the environment.
- Alpha Radiation. Alpha radiation is a type of energy released when certain radioactive elements decay or break down.
- Uranium. Uranium is a radioactive element that can be found in soil, air, water, rocks, plants and food.
- Radium.
- Radon.
- Polonium.
The decay of unstable atoms releases radiation, a phenomenon called radioactivity. As unstable atoms exist in all matter, we are surrounded by natural radiation. Radiation can also come from man-made sources, through military, medical or industrial applications. This is commonly referred to as radioactivity.
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay.
Half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay (change spontaneously into other nuclear species by emitting particles and energy), or, equivalently, the time interval required for the number of disintegrations per second of a radioactive
Natural radioactivity is a purely nuclear phenomenon. The nucleus of a radioactive substance is unstable and such an unstable nucleus undergoes spontaneous breakdown (disintegration). The process continues until a stable nucleus is obtained.
Similarly, many other materials, especially metals, are subject to neutron activation. A piece of steel containing small amounts of stable cobalt when irradiated with low energy neutrons will produce radioactive products from both the iron and the cobalt in the metal (as well as other possible species).
Nuclear Waste Neutralization Using Hydroxy Gas. A process for neutralizing radioactive wastes such as Plutonium and Americium is demonstrated using Hydroxy Gas in combination with a metal matrix.
In chemistry and physics, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines an isotope's mass number (nucleon number). Until the 1960s, nucleons were thought to be elementary particles, not made up of smaller parts.
There are several physical processes that generate cosmic gamma rays:
- A high-energy particle can collide with another particle.
- A particle can collide and annihilate with its anti-particle.
- An element can undergo radioactive decay.
- A charged particle can be accelerated.
An unstable nucleus spontaneously emits particles and energy in a process known as radioactive decay. The term radioactivity refers to the particles emitted. When enough particles and energy have been emitted to create a new, stable nucleus (often the nucleus of an entirely different element), radioactivity ceases.
A gamma ray, or gamma radiation (symbol γ or. ), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves and so imparts the highest photon energy.
What causes atoms to be radioactive? An atom is unstable (radioactive) if these forces are unbalanced; if the nucleus has an excess of internal energy. Instability of an atom's nucleus may result from an excess of either neutrons or protons.
Radioactivity can occur both naturally and through human intervention. An example of artificially induced radioactivity is neutron activation. A neutron fired into a nucleus can cause nuclear fission (the splitting of atoms). These nuclei then become unstable and emit radiation that attacks the cancer cells.
The synthetic elements are those with atomic numbers 95–118, as shown in purple on the accompanying periodic table: these 24 elements were first created between 1944 and 2010.
Radioactive sources are used to study living organisms, to diagnose and treat diseases, to sterilize medical instruments and food, to produce energy for heat and electric power, and to monitor various steps in all types of industrial processes. Tracers are a common application of radioisotopes.
The radiation dose absorbed by a person (that is, the amount of energy deposited in human tissue by radiation) is measured using the conventional unit rad or the SI unit gray (Gy). The biological risk of exposure to radiation is measured using the conventional unit rem or the SI unit sievert (Sv).
The EM spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency. The common designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma rays.
Radiation Examples
- ultraviolet light from the sun.
- heat from a stove burner.
- visible light from a candle.
- x-rays from an x-ray machine.
- alpha particles emitted from the radioactive decay of uranium.
- sound waves from your stereo.
- microwaves from a microwave oven.
- electromagnetic radiation from your cell phone.
The radiation one typically encounters is one of four types: alpha radiation, beta radiation, gamma radiation, and x radiation. Neutron radiation is also encountered in nuclear power plants and high-altitude flight and emitted from some industrial radioactive sources.
Radioactivity is a part of our earth - it has existed all along. Man has always been exposed to natural radiation arising from the earth as well as from outside the earth. The radiation we receive from outer space is called cosmic radiation or cosmic rays.
Radiation cannot be detected by human senses. A variety of instruments are available for detecting and measuring radiation. The most common type of radiation detector is a Geiger-Mueller (GM) tube, also called a Geiger counter.
Now, let's look at the different kinds of radiation. There are four major types of radiation: alpha, beta, neutrons, and electromagnetic waves such as gamma rays. They differ in mass, energy and how deeply they penetrate people and objects.
