RADIUM, RADIATION AND RADIOACTIVITY

    The fluorescent glow and the invisible ray sparked a hullabaloo in the late 19th century. Scientists questioned their understanding of atoms. They ventured deep into the atomic nuclei to discover the spectacular phenomena of radioactivity.

Image Source-Inductiveload, NASA / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/)

So What is Radiation? 
  Radiation is the dissipation of energy by means of waves/particles that travel at the speed of  300,000 km/sec. Eminent scientists like Pierre and Marie Curie, Henri Becquerel and Wilhelm Röntgen probed into the interior of atoms.
    Radiation happens inside the atoms. The atoms are made up of electrons, protons and neutrons. Electrons are always moving at high speed and whenever they jump from one energy level to another they emit radiation. Also when a neutron knocks off the nucleus of another atom, it produces radiation.
    There are different types of radiation viz; visible light, infrared, ultraviolet, microwave, radio, alpha-beta-gamma ray, neutron ray; many falling under the electromagnetic spectrum.

  Now comes Radioactivity...
   Radioactivity/ radioactive decay is the property by virtue of which an unstable atomic nuclei spontaneously disintegrates into a stable one. Uranium nuclei disintegrates to lead, emitting nuclear radiation. The discovery of radioactivity started from Wilhelm Röntgen followed by Henri Becquerel. But it was Marie Curie who coined the term "radioactivity".
     The only difference between radiation and radioactivity is as follows. A campfire emits radiation(thermal) but it is not radioactive and does no harm. Whereas Uranium, a radioactive substance emits deadly radiation. That is, all radioactive substances emit radiation but all radiative substances are not radioactive.

Ionizing and Non-Ionizing Radiation...
     Ionizing radiation is the high frequency shorter wavelength radiation. Alpha particles, Beta ray, Gamma ray and Neutron ray fall under this category, having extreme penetrating properties. They can strip the electrons of other atoms thereby ionizing them. They can penetrate living tissue and alter the DNA structure.
     Non-Ionizing is the low frequency, longer wavelength electromagnetic radiation. Microwaves, Radiowaves, visible light, infrared ray fall under this category. They donot pose much harm to living organisms.

   Finally Radium!
Radium was discovered in 1898 while the Curie couple were extracting uranium from pitchblende. They found that unrefined pitchblende was more radioactive than uranium and reasoned that it must contain another radioactive substance. The new element had a striking similarity with barium with a greenish glow. Thus the name 'Radium' was given by Pierre. The two pioneers of radioactivity worked in a shabby room, storing all the radium with them. Radium's characteristic glow made them analogous of stars in the night sky. Pierre and Marie shared with Henri Becquerel the Nobel prize for physics in 1903. Pierre died in an accident in 1906. Marie continued her work and got the Nobel prize for chemistry in 1911. She died in 1934 due to radiation induced leukemia. And their discovery? That's still glowing....