Back to: Jss3 Basic Science
WEEK: 1 & 2
Matter is made up of atoms. Protons, neutrons, and electrons are all parts of an atom. Protons and neutrons are in the center of the atom, which is called the nucleus. Electrons move around the atom. Some atomic nuclei (nuclei is the plural form of the word “nucleus”) can break apart and release particles. A French physicist named Antoine Henri Becquerel was the first person to notice this phenomenon, which is called “radioactivity.”
This lesson will teach you about the different types of radioactive elements, the different types of radiation, and the benefits and risks of radioactive rays.
Meaning Of Radioactivity
Radioactivity is when atomic nuclei break apart on their own by giving off subatomic particles called alpha and beta particles or electromagnetic rays called gamma rays. Unstable atomic nuclei will break apart on their own to make more stable nuclei. Radiation is the energy and particles that are given off when something breaks down. The process by which unstable nuclei break down in nature is called “natural radioactivity.” When unstable nuclei are made in a lab, the breakup is called “induced radioactivity.”
Types of radioactive elements
There are two types of radioactive elements: Natural radioactive (those that come from nature) and Artificial raioactive (those that are made in a lab).
Except for technetium and promethium, most naturally occurring radioactive elements are between 84 and 118 on the periodic table. Some of them are uranium, radon, thorium, radium, plutonium, and others.
Types Of Natural Radioactive
Radiation comes in three different forms: alpha radiation, beta radiation, and gamma radiation.
The Alpha Particles
This is a stream of alpha particles, which are positively charged and have an atomic mass of 4 and a charge of 2. (a helium nucleus). When an alpha particle is thrown out of a nucleus, its mass number drops by four and its atomic number drops by two. For instance:
The alpha particle is made up of the nucleus of helium.
This is a stream of beta particles, which are made up of electrons. When a beta particle is sent out, a proton is made from a neutron in the nucleus. So, the number of the nucleus’s atoms stays the same, but the number of the nucleus’s atoms goes up by one.
Gamma rays are photons with a very short wavelength and a lot of energy (0.0005 to 0.1 nm). Gamma radiation comes from a change in energy within the nucleus of an atom. Gamma emission does not change the number of atoms or the mass of an atom. Gamma emission often happens at the same time as alpha and beta emissions. This is because an excited nucleus drops to a lower, more stable energy state as it loses energy.
Different Types of Nuclear Radiation
Because different nuclei are different in how stable they are, there are four types of nuclear reactions.
- Radioactive decay: This means that an alpha particle, a beta particle, or gamma radiation is released, and a slightly lighter and more stable nucleus is made.
- Nuclear disintegration: Nuclear disintegration happens when alpha particles, protons, deuterons (deuterium nuclei, 12H), neutrons, or other particles hit a nucleus. In a process called nuclear disintegration, the unstable nucleus gives off a proton or a neutron and gets more stable.
- Fission: Fission is the process by which a very heavy nucleus splits into two nuclei with a medium amount of mass.
- Fusion: This is the process by which nuclei with less mass join together to make nuclei with more mass that are more stable.
Artificial Radioactive elements are not found in nature; instead, they are made in a lab. Rutherford was the first person to find out how to make radioactivity happen on purpose. He did this by hitting the 14N nuclei of nitrogen with alpha particles (7 protons and electrons). Rutherford made O, which has eight protons and eight electrons. Rutherford drew the conclusion from this that atoms of one element can be turned into atoms of another element.
Uses Of Radioactivity
- There is a wide variety of applications for radioactive materials, including:
- As “radiotracers,” tiny quantities of radioactive substances can be consumed to observe how specific chemicals are absorbed by the body. A health researcher can choose to use a radioactive isotope of a common element, mix it in, and then use sensitive radiation detectors to see where it ends up in the body if he is interested in how a specific element is distributed by the body after it is ingested. These are frequently employed in research to determine how drugs are absorbed and transported in the body.
- The mantles for gas and kerosene lamps are made of thorium, a naturally occurring radioactive element because thorium oxide glows brilliantly when heated.
- In nuclear power plants, uranium and plutonium are used to produce electricity.
- Radioactive materials are also used in the production of nuclear weapons.
- Some radioactive substances, such as Americium-241, are utilized in smoke detectors.
- Some radioactive substances are applied in the management of cancer. Gamma rays are used to treat cancerous growth in this manner. The name of this type of treatment is radiotherapy.
- · Since uranium has a very long half-life, it is possible to determine the approximate age of a rock by calculating the amount of uranium still present in it.
Dangers Of Radioactive Rays
- When radioactive substances are handled improperly, they can also have negative effects. Some of the dangers of radioactivity are:
- Radiation can lead to cancer in people and other living things, even in small doses. Alpha particles (helium nuclei), electrons (beta rays), and helium photons (fast-moving photons) can collide with other molecules and alter their structure. The genetic information may be harmed if this occurs to a DNA molecule, leading to genetic mutation and occasionally making a cell cancerous.
- When exposed to radiation in high doses for a brief period of time, burns can also result, similar to a sunburn.
- Radiation exposure that is too high can result in cancer. Radioactive iodine, for instance, is easily absorbed by the body and gets incorporated into bones, making it challenging to get rid of from the body.
- Radiation emissions have a long-term risk of causing bone cancer.
- Weapons of mass destruction are constructed using radioactive materials.