[Physics Class Notes] on Alpha Particle Mass Pdf for Exam

Radiation is one of the forms of energy that occurs when an unstable parent nucleus undergoes radioactive decay. Radiations travel a certain distance from their source in the form of energized waves/particles. The particles are alpha, beta, and gamma; these particles have different attributes and effects. We will focus on the alpha particle. Now, let’s understand what alpha particles are.

Alpha particles were named after the Greek alphabet ‘α’. The symbol for the alpha particle is α or α²⁺. As these particles are congruent to Helium nuclei. That’s why alpha particles can be written as He²⁺ or 24He indicating a Helium ion with a +2 charge (lacking two electrons). 

Alpha particles are known as α-rays or alpha radiation; these particles comprise two protons and two neutrons bound together into a particle isotropic to Helium-4 nuclei. These particles are developed during the α-decay process.

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In this article, we will learn about alpha particles. So, let us get started with its characteristics.

Characteristics of Alpha Particle

Fundamental Properties of Alpha Particles

• Alpha particles carry double the positive charge of the proton, i.e., equal to the charge on the Helium nucleus.

• The mass of an α-particle is four times the mass of a Hydrogen atom, i.e., equivalent to the mass of the Helium atom.

(The above two properties prove that an alpha particle is equal to the Helium atom which has lost its two orbital electrons or a doubly ionized Helium atom).

• The velocity of alpha particles ranges between 1.4 х 10⁷ m/s to 2.1 х 10⁷ m/s, relying on the source emitting/radiating it.

• Because of the large mass of alpha particles, the penetrating power of these particles is lesser. It is 1/10³ times the penetrating power of beta rays and 1/10⁵ times that of the gamma rays. 

• Despite having a large size and low perforating power, alpha radiation can stop by a 0.02 cm thick aluminium sheet.

• On being stopped, alpha particles give rise to heating effects. Though alpha particles have low perforating power, they can cause burns on the human body.

• Because of their large mass and high-stepping speed, these particles have excessive ionizing efficiency. It means a single alpha particle can bring forth thousands of ions before being absorbed.

• The distance an alpha particle travels in the air relies on the radioactive source creating it. At the normal pressure in air, the range of alpha particles deviates from 3 to 8 cm.

• Alpha particles produce fluorescence in certain substances, like Barium-Platinocyanide and Zinc-Sulphide (ZnS).

• Alpha particles fractionally affect the photographic plates.

• Alpha particles are deflected by both electric & magnetic fields at smaller angles. 

• Alpha particles are garbled while passing through thin metal foils. 

• Most of the particles were disordered at small angles; however, a few of them deflected at an angle greater than the right angle.

Uses of Alpha Radiations

Alpha radiations are very popular in day-to-day applications. Some of its uses are:

We use alpha particles in cancer treatment. While treating the cancer patient, doctors use a technique called Unsealed Source Radiotherapy. This technique involves inserting alpha particles like Radium-226 in tiny amounts into cancerous masses. We use Radium-223 to treat bone cancer.

Static Eliminator is a common technique used in industries like paper mills. This technique helps eliminate static electricity in industries. What happens in this method is, alpha particles attract free electrons towards themselves; thereby, reducing the potential of the static electricity.

We can increase the life of a battery by using alpha radiation as the source of energy. Alpha radiations of Plutonium-238 serve as the best fuel source for heart pacemakers.

Alpha particles are the best source of energy, especially in remote areas. Alpha radiations of Strontium-90 serve as the best source to increase the lifespan of batteries.

Smoke detectors typically fall into the following two categories:

1. Photoelectric smoke detector

2. Ionization smoke chamber detector.

Ionization smoke chamber detectors are common household items that keep us safe by alerting smoke in our homes. These detectors use a small amount of isotope of Americium, i.e., Americium-241 as the source of alpha particles. 

Alpha radiations ionize the air molecules, allowing a small current to flow between electrodes. This current rings an alarm.

Conclusion

Thus after reading this write-up on alpha particles we have understood what alphas particles are, how they are generated, their properties and characteristics and their uses. It has also helped us understand how important alpha particles are from the application point of view.

As
a Physics student who will be handling such devices in the future, one must remember these particles are radioactive and can be damaging to your health. Thus when dealing with alpha particles a lot of care is taken.

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suggests you go ahead and learn about beta particles (formed during beta decay) and gamma decay which produces gamma particles. can also help you understand the topic of applications of Radioactivity in detail.