A series of scientific discoveries involving four scientists lie behind what we now know as alpha, beta, and gamma radiation:
It was Henri Becquerel who accidentally discovered radioactivity in 1896.
Marie Curie coined the term “radioactivity” when she and Pierre Curie started working on the phenomenon that Becquerel had discovered. After extracting pure uranium from the ore, the Curies realized that the remainder was more active than uranium.
Their conclusion, naturally, was that the ore had radioactive materials other than uranium. That’s the story behind the discovery of polonium and radium. It took four more years to isolate polonium and radium from the ore to study their chemical properties.
Ernest Rutherford discovered three types of emissions from radioactive substances as he experimented with them between 1900 and 1903. He named them alpha, beta, and gamma radiation. They differ in their ability to penetrate matter.
What Is Alpha, Beta, And Gamma In Chemistry?
Radioactivity is the process of unstable nuclei spontaneously decomposing to attain a more stable nuclear status. The decaying process continues until the unstable nuclei gain stability. Alpha, beta, and gamma, as named by Rutherford, are three such processes.
Alpha Particles
Alpha (α) is the largest particle with the least penetrative power. Alpha particles carry a positive charge. An alpha particle consists of two neutrons and two protons bound together. The alpha particle later got identified as the helium-4 nucleus.
Alpha particles have the greatest mass among the three types of radioactive emissions. The mass of an alpha particle is about 8000 times more than the mass of a beta particle. This large size reduces the penetrative power of an alpha particle.
Beta Particles
Beta particles (β) are high-energy electrons or positrons that carry a negative charge. Considerably smaller in size than alpha particles, beta particles have higher penetrative power.
Gamma Rays
Gamma rays (γ) are not particles with a mass. They are a kind of electromagnetic radiation that is considerably higher in energy than x-rays. As a form of energy, gamma rays have no size or mass.
Gamma rays are far more harmful to humans than x-rays. The charge of gamma rays, however, is neutral.
How Do You Know If It’s Alpha Or Beta Decay?
A material with unstable nuclei is a radioactive material. When an unstable atomic nucleus loses energy through radiation, we call it radioactive decay. Simply put, when a radioactive nucleus breaks down spontaneously, it releases energy and matter from the nucleus.
Matching the three types of emissions from radioactive materials, there are three types of radioactive decay: alpha, beta, and gamma. Simply put In simple words, alpha, beta, and gamma decay result from three basic forces working in the nucleus: strong, weak, and electromagnetic.
Alpha Decay
In alpha decay, the nucleus splits into two parts with one of the parts speeding off into space. The atomic number of the nucleus reduces by two, therefore. Its mass number decreases by four, as two protons and two neutrons get removed.
Alpha decay is the result of the strong force in the nucleus. It is a very slow process and usually leaves the nucleus in a state of excitement.
Beta Decay
In beta decay, which has a negative charge, a neutron changes into a proton, which emits an electron, and an antineutrino. The mass number remains unaltered while the atomic number increases by one.
This is beta decay minus. There is a different kind of beta decay: the plus variety. The process gets reversed here. A proton transforms into a neutron, which emits neutrino and positron.
The mass number remains the same in this version of decay also. The atomic number, however, goes up by one.
Beta decay is the expression of the weak force in the nucleus. Like alpha decay, this also is a slow process. The nucleus remains in an excited stage due to beta decay also.
Gamma decay
Gamma decay is the release of the electromagnetic force in the nucleus. Gamma emission can stabilize the state of the energy in the nucleus.
Which Is More Dangerous: Alpha, Beta, Or Gamma?
This question is more complex than it seems at first, as radiation can cause damage both from the outside and from inside an organism. The capacity of alpha, beta, and gamma rays pose varying levels of danger externally and internally.
Alpha rays have poor penetration power. They can cause little harm from outside. The outer layer of dead skin in humans, a thick sheet of paper, or a layer of clothes can resist alpha penetration.
However, alpha particles also have the greatest mass, which implies that they have the greatest ionizing power. If an alpha particle somehow gets into the system through inhaling or swallowing, they become the most dangerous.
Chances of alpha particles getting inside the system occur only in situations of a nuclear accident or explosion. Once inside, alpha particles can cause maximum damage to the tissues of humans and other living organisms.
Beta particles are smaller and have less tissue-damaging power when inside an organism. However, they have greater penetrative power. From the outside, beta particles can burn human skin. It would be similar to a severe sunburn.
Gamma rays have the highest penetration power. A living organism such as a human being exposed to gamma rays faces a high risk of having bone marrow and internal organs damaged.
Gamma rays can pass through a body, damaging tissue and DNA in the process. Scientists consider gamma rays to be the most dangerous form of radiation.
What Are The Properties and Applications Of Alpha, Beta, And Gamma Radiation?
Alpha particles are positive, heavy, and slower in its movement in comparison to other kinds of nuclear radiation. The travel speed of alpha particles is 5 to 7% of the speed of light.
Radiotherapy in cancer treatment uses alpha particles to kill the cancerous cells. Because of their low penetration power, they cannot damage the healthy cells surrounding the cancerous part.
One-thousandth of the mass of a proton is the mass of a beta particle. Beta particles carry either one negative charge – an electron, or one single positive charge – a positron. Because of their small mass, beta particles can travel almost at the speed of light.
Beta particles get used as tracers for medical imaging. They also have therapeutic uses in bone and eye cancer treatment. Smoke detectors also use beta particles. Sometimes, beta particles are used for quality control. Checking the thickness of paper, for instance.
Gamma has no mass and no electrical charge. It can travel at the speed of light. There is some application of gamma rays in oncology, and for sterilizing medical instruments.