Radium vs. Iridescent - What's the difference?

Main Difference

The main difference between Radium and Iridescent is that the Radium is a element with the atomic number of 88 and Iridescent is a property in which fine colors, changeable with the angle of view or angle of illumination, are produced on a surface by the interference of light that is reflected from both the front and back of a thin film.


  • Radium

    Radium is a chemical element with symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) on exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are highly radioactive, with the most stable isotope being radium-226, which has a half-life of 1600 years and decays into radon gas (specifically the isotope radon-222). When radium decays, ionizing radiation is a product, which can excite fluorescent chemicals and cause radioluminescence. Radium, in the form of radium chloride, was discovered by Marie and Pierre Curie in 1898. They extracted the radium compound from uraninite and published the discovery at the French Academy of Sciences five days later. Radium was isolated in its metallic state by Marie Curie and André-Louis Debierne through the electrolysis of radium chloride in 1911.In nature, radium is found in uranium and (to a lesser extent) thorium ores in trace amounts as small as a seventh of a gram per ton of uraninite. Radium is not necessary for living organisms, and adverse health effects are likely when it is incorporated into biochemical processes because of its radioactivity and chemical reactivity. Currently, other than its use in nuclear medicine, radium has no commercial applications; formerly, it was used as a radioactive source for radioluminescent devices and also in radioactive quackery for its supposed curative powers. Today, these former applications are no longer in vogue because radium's toxicity has since become known, and less dangerous isotopes are used instead in radioluminescent devices.

  • Iridescent

    Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change colour as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, butterfly wings and seashells, as well as certain minerals. It is often created by structural coloration (microstructures that interfere with light). Pearlescence is a related effect where some or all of the reflected light is white, where iridescent effects produce only other colours. The term pearlescent is used to describe certain paint finishes, usually in the automotive industry, which actually produce iridescent effects.


  • Radium (noun)

    a radioactive metallic chemical element (symbol Ra) with an atomic number of 88.

  • Iridescent (adjective)

    Producing a display of lustrous, rainbow-like colors; prismatic.

  • Iridescent (adjective)

    Brilliant, lustrous, or colorful.

Oxford Dictionary

  • Radium (noun)

    the chemical element of atomic number 88, a rare radioactive metal of the alkaline earth series. It was formerly used as a source of radiation for radiotherapy.

Webster Dictionary

  • Radium (noun)

    An intensely radioactive metallic element found (combined) in minute quantities in pitchblende, and various other uranium minerals. Symbol, Ra; atomic weight, 226.4. Radium was discovered by M. and Mme. Curie, of Paris, who in 1902 separated compounds of it by a tedious process from pitchblende. Its compounds color flames carmine and give a characteristic spectrum. It is divalent, resembling barium chemically. The main isotope of radium found in pitchblende, radium-226, has a half-life of 1620 years, decaying first by alpha emission to radon.

  • Iridescent (adjective)

    Having colors like the rainbow; exhibiting a play of changeable colors; nacreous; prismatic; as, iridescent glass. See iridescence.

Princeton's WordNet

  • Radium (noun)

    an intensely radioactive metallic element that occurs in minute amounts in uranium ores

  • Iridescent (adjective)

    varying in color when seen in different lights or from different angles;

    "changeable taffeta"

    "chatoyant (or shot) silk"

    "a dragonfly hovered, vibrating and iridescent"

  • Iridescent (adjective)

    having a play of lustrous rainbow-like colors;

    "an iridescent oil slick"

    "nacreous (or pearlescent) clouds looking like mother-of-pearl"

    "a milky opalescent (or opaline) luster"

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