Francium Facts

Francium Facts
Francium (Fr) has an atomic number of eighty-seven, and the same number of protons in the nucleus of one atom. It is the most unstable of the first one hundred elements.
Interesting Francium Facts:
Even as early as 1870, scientists believed there would be another element in the alkali metals family that was higher than caesium, going to far as to predict it at number eighty-seven.
Prior to its discovery, it was simply referred to as eka-caesium.
There were four false reports of the discovery of this element due to either research errors or incomplete research before francium was legitimately discovered.
Marguerite Perey finally discovered francium in 1939 at the Curie Institute.
Unlike the previous researchers, Perey discovered francium in the decay residue of actinium-227.
Actinium-227 is the primary natural source of francium, while only trace amounts can be found in minerals of uranium and thorium.
Its occurrence in uranium minerals is believed to be only one francium atom for every 1,000,000,000,000,000,000 (one quintillion) atoms of uranium.
Much like astatine, francium only occurs as the state of decay of other radioactive elements, so it is estimated that there is no more than thirty grams of francium in the Earth's crust at any time.
As of 2012, there has not been enough francium produced to weigh the amount.
It has the highest equivalent weight of all elements.
Both its melting point and its boiling point can only be estimated due to its rarity and its rate of decay, but they are estimated to be 27-degrees Celsius and 677-degrees Celsius, respectively.
Francium has thirty-four known isotopes, with only two of them occurring in nature.
The most stable isotope, Fr-223, has the longest half-life at 21.8 minutes.
The least stable isotope, Fr-215, has a half-life that—in its metastable isomer state—is only 3.5 nanoseconds.
It is the most unstable of all elements that occur naturally.
Due to this high-speed rate of decay and its rarity on Earth, there are no practical applications of francium in industry or commerce.

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