Types of Radiations- Definition, Types of Radiation, Sources, Nuclear Radiations, Characteristics and Properties of Nuclear Radiations, Practice Problems and FAQ

Let us list some of the items which we think are very useful and without which we may think it is not possible to live today. Are the following sun, fire, cell phone, television, Wifi router, X-rays, or medical scanner, in your list? Though useful, there is a common thing among them which but affects our existence itself. Do you know what is that? Yes, it is Radiation.

Let's learn about the types, and characteristic properties of radiation and compare different types of radiation in this article.

Table of Content

• Definition
• Types of Radiation
• Sources of Radiations
• Different Characteristics Properties of Emitted Radiation
• Practice Problems
• Frequently Asked Questions-FAQ

Definition

Radiation is a propagating energy-that is energy in motion in space. Energy may or may not be associated with material particles. Sun rays, which we look for every day are electromagnetic radiation propagating in waves while radioactive substances emit particles with energy.

Radiations associated with an electric and magnetic field, travel through space at the speed of light. This energy has wave-like properties. Radiation is also known as "electromagnetic waves. For example, X-rays, and UV rays, are examples of electromagnetic radiation. Alpha and beta are particles with energy.

Types of Radiation:

Radiations are generally classified as

1. Ionizing radiations and
2. Nonionizing radiations

Ionizing Radiations:

These are electromagnetic radiations with a high energy of about 10eV. They break atoms and molecular bonds and produce oppositely charged species. They have low penetrating power, and will not pass deep into substances.

Nonionizing radiations.

These are either low-energy radiations s of microwave, sound waves or nuclear emissions of alpha, beta and gamma radiations.

Sources of Radiation:

Anything around us is a source of radiation. But they differ in the quantum of energy they release. In that way, the Sun is the major source of all radiation.

But the kitchen burner, our mobile, television, medical imaging techniques like X-rays, ultra scanner, Wifi router, and our own earth walls etc emit radiations. Remember over exposure to noon sun rays or, to stay in closed indoors, having mobile close to heart, undergoing repeated scanning etc are all activities to be reduced if not to be entirely avoided as exposure to any radiations is injurious to health.

Nuclear Radiations:

Generally, during a nuclear reaction, three different types of radiation are emitted:

a) Alpha particles: Alpha particle is also known as Alpha radiation or Alpha ray. It is a positively charged particle emitted by the decay of various radioactive materials. The alpha particle's mass is due to the bonding of two protons and two neutrons. It is represented by the symbol '${\alpha }^{\text{'}}$' which is doubly ionised helium nucleus which consists of 4 unit of atomic mass and 2 units of a positively charged particle. When the alpha particle is emitted the atomic mass decreases by 4 units and the atomic number of the daughter nuclei decreases by 2 units respectively.

b) Beta particles: A beta radiation, is a high-energy electron or positron emission from a radioactive atomic nucleus. Two types of particles are possible and accordingly classified as ($\beta$-) decay and ($\beta$+)decay. ($\beta$-) decay is associated with emission of electrons while (+)decay, is the release of positrons. Beta particles because of their energy can ionize molecules.. Because of the mass they will be more ionising than gamma rays. On the same reason they are less ionising than the heavier alpha particles.But larger the ionising power lesser will be their penetrating power. The greater the ionising effect, the larger the damage particularly to a living tissue. but also the lower the penetrating power of the radiation. When ($\beta$-) decay takes place in the form of an electron it results in an increase in the atomic number of the daughter nuclei by 1 unit without changing its atomic mass.

C) Gamma rays: A gamma ray is a type of penetrating electromagnetic radiation produced by the radioactive decay of atomic nuclei. It is represented by the  Y symbol. It is composed of electromagnetic waves with the shortest wavelengths, which are typically shorter than those of X-rays and have higher penetrating power than alpha and beta particles. It is a form of energy in which there is no change in the atomic mass or atomic number when gamma rays are emitted.

Different Characteristic Properties of Emitted Radiation

Practice problems

Q1. What will be the atomic number and mass number respectively of the daughter nuclei if uranium emits two-particle?

A. 88, 238
B. 90, 232
C. 88, 232
D. 88, 230

Answer: (D)

Solution: When one particle is emitted mass number of the daughter nucleus decreases by 4 and the atomic number decreases by 2. According to the given question when two alpha particle is emitted mass number decreases by 8 unit and the atomic number decreases by 4 unit,

Therefore,

Mass number of the daughter nucleus =238-8=230

Atomic number of the daughter nucleus=92-4=88

So, option (D) is correct

Q2. Select the correct option with respect to the radiation emitted during the radioactive process

A. When $\alpha$ one particle is emitted resulting nuclei are isobar of the parent nuclei
B. When $\gamma$ particle is emitted resulting nuclei emit energy in the form of electromagnetic radiation
C. When one $\beta$ particle is emitted the resulting nuclei is an isotope of the parent nuclei
D. Both A and B is correct

Answer: (B)

Solution: When $\beta$ the alpha particle is emitted atomic number decreases by 2 unit and the mass number decreases by 4 unit respectively but isobar is defined as the element which has same atomic mass but a different atomic number.

When ($\beta$) decay takes place in the form of an electron it results in an increase in the atomic number of the daughter nuclei by 1 unit without changing its atomic mass. But isotope is defined as the element which has the same atomic number but different atomic mass

Therefore option (A) and (C) is incorrect

A gamma ray is a type of penetrating electromagnetic radiation produced by the radioactive decay of atomic nuclei. Therefore option (B) is correct

Q3. Which of the following option is correct with respect to the characteristics properties of the radiation emitted during the nuclear reaction?

A. Penetration power of $\beta$ radiation is more than rays
B. Both $\alpha$ and $\beta$ particle moves with the same kinetic energy when emitted
C. Velocity of particles is more than the particles
D. When $\beta$ particle is emitted both atomic number and mass number of the parent nuclei changes

Answer: (C)

Solution: Penetration power of the gamma rays is more than beta particles as gamma rays travel with the speed of the light with higher velocity as compared with a beta particle.

In the case of kinetic energy alpha particles moves with higher kinetic energy as compared to the beta particle.

Gamma rays are the form of electromagnetic radiation which move at the speed of light and have higher velocity as compared with alpha particles.

Beta particles are similar to the electron which contains (-1) charge and are represented as . When the beta particle is emitted from a radioactive element it increases the atomic number of the daughter nuclei by one unit without changing the atomic mass of the daughter nucleus. Therefore option (C) is correct.

Q4. Select the correct option from the given statement when one $\beta$ particle is emitted from a parent nuclei having an atomic number as 'Z' and mass number 'A'.

A. Atomic number of the daughter nuclei will be (Z+1) where as the mass number will remain unchanged
B. Atomic number of the daughter nuclei will be (Z-1) where as the mass number will remain unchanged
C. Mass number of the daughter nuclei will be (A+1) where as the atomic number will remain unchanged
D. Atomic number of the daughter nuclei will be (Z-1), where as mass number of the parent nucleus will be (A+1)

Answer: (A)

Solution: Beta particles are similar to the electron which contains (-1) charge and are represented as . As the number of nucleons and the number of protons remains conserved during a nuclear reaction, therefore, when the beta particle is emitted from a radioactive element it increases the atomic number of the daughter nuclei by one unit without changing the atomic mass of the daughter nucleus. Therefore, option (A) is correct.

Frequently Asked Questions

Q1. What is the harmful effect of gamma radiation when subjected to the human body?
Answer: High-dose radiation exposure over a short period of time can cause radiation sickness (also known as acute radiation syndrome or radiation poisoning) and even death. Radiation sickness symptoms include nausea, confusion, fainting and vomiting, diarrhoea, skin and mouth sores, hair loss, and bleeding. Many cases of radiation sickness resulted from the atomic bomb blasts in Hiroshima and Nagasaki. Some cases have since arisen as a result of nuclear power plant accidents, such as those in Chernobyl and Fukushima

Q2. What is the source of beta particles?
Answer: Beta particles ($\beta$) are small, negatively charged particles emitted from an atom's nucleus during radioactive decay. These particles are emitted by unstable atoms such as carbon-14, hydrogen-3 (tritium), and strontium-90.

${{}^{15}}_{8}O \to {{}^{15}}_{7}N{+}_{+1}^{0}e$

${{}^{32}}_{15}P\to {{}^{32}}_{16}S{+}_{-1}^{0}e$

Q3. What are the factors upon which the range of alpha particles in the gas depends upon?
Answer: The range of the alpha particle in the gases depends on different factors like pressure, temperature and nature of the gas. The range of the alpha particle is inversely proportional to the pressure and inversely proportional to the absolute temperature.

Q4. How can we detect the alpha, beta and gamma particles emitted during the radiation?
Answer: Alpha particles can be detected by passing through a spark detector containing a grating of wires separated by a distance of about 1 mm and connected to earth. The spark detector does not contain any gas like Geiger- Muller counter but works on the same principle of creating aan electrical spark on coming into contact .

A Geiger-Müller counter (ionisation detector) is used to detect betas and gammas. The instrument is a cylindrical conducting vessel with a narrow window for the ionizing radiation to enter.. The cylinder is filled with an inert gas like argon but at lower than atmospheric pressure. A metal wire is fixed along the axis of the cylinder and a high voltage of around 900 V, is maintained between the cylinder walls and the central wire. Radiation disintegrates the inert gas to form.electron-ion pairs. The movement of the electrons towards the anode and that of the positive ion towards cathode create mild current. The current is amplified and recorded for identification of the radiation..