Transformation of Elements

There are two types of radioactivity – natural and artificial radioactivity.

The phenomenon of radioactivity was first discovered by Henri Becquerel

Natural radioactivity is the spontaneous disintegration of the nucleus of an atom during which α-particle or β-particle, or gamma rays or a combination of any or all the three and heat (or energy) are released.

When a radioactivity element undergoes radioactive decay, it may emit either α-particle, β-particle or γ rays. This changes the atomic number of the element, hence a new element is formed. For example, Radium-226 decays by emitting an α-particles to turn into a new element Radon. Radium-226 has a mass number 226 and an atomic number 88 and hence it is denoted by 22688Ra. The α-particles it emits is a Helium nucleus denoted by 42He. So when Radium 226 emits an α-particle. We can write a nuclear equation:

22688Ra → 42He + 22286Rn + energy

(Radon – 222)

Radon – 222 decays to Radium – 222 by emitting 2 β-particles. When the nucleus of an atom emits a β-particle (i.e. an electron), the atomic number of the atom increases by one unit, but its mass number remains unaltered. Hence since two β-particles are emitted from Radon 222 we can write the equation

22286Rn → 2 0-122288 Ra + energy

Uranium-238 decays by emitting two α-particles and two β-particles to thorium -230. Hence we can write the nuclear equation thus:

23892U → 2 42H + 2 0-1e + 23090Th + energy

↑           ↑

2α-particles 2β-particles

Thorium-234 decays by emitting a β-particle to the element Protactinium-234 thus:

23490 Th→ 0-1e ­23491Pa + energy

Generally we represent alpha (α) decay by

ABX→42He + (A-4)(z-2)Y


and Beta (β)-decay by AZX→ 0-1e ­A(Z+1)Y


Gamma radiation (γ) is a form of light, emitted as photons of energy hf, and has zero mass number and zero charge (A = 0, Z = 0).

To balance a nuclear equation we ensure that the sun of the atomic numbers, Z (subscripts) must be the same on the two sides of the equation. Also the sum of the mass numbers A (superscripts) must be the same on the two sides of the equation.

Join Discussion Forum and do your assignment: Find questions at the end of each lesson, Click here to discuss your answers in the forum

Ad: Get a FREE Bible: Find true peace. Click here to learn how you can get a FREE Bible.

For advert placement/partnership, write [email protected]

Download our free Android Mobile application: Save your data when you use our free app. Click picture to download. No subscription. stoplearn

We are interested in promoting FREE learning. Tell your friends about Click the share button below!