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Francium-223 is the most stable isotope, with a half-life of 21.8 minutes, [8] and it is highly unlikely that an isotope of francium with a longer half-life will ever be discovered or synthesized. [22] Francium-223 is a fifth product of the uranium-235 decay series as a daughter isotope of actinium-227; thorium-227 is the more common daughter. [23]
As a result, element 173 is expected to behave chemically like an alkali metal, and one that might be far more reactive than even caesium (francium and element 119 being less reactive than caesium due to relativistic effects): [90] [19] the calculated ionisation energy for element 173 is 3.070 eV, [91] compared to the experimentally known 3.894 ...
The CsFr molecule is predicted to have francium at the negative end of the dipole, unlike all known heterodiatomic alkali metal molecules. Francium superoxide (FrO 2) is expected to have a more covalent character than its lighter congeners; this is attributed to the 6p electrons in francium being more involved in the francium–oxygen bonding. [4]
At last count 96/97 of the 97 elements (hydrogen through einsteinium, except astatine and francium) isolated in pure form and in macroscopic quantities have images.; There are few images of very low encyclopedic quality for which it should be relatively easy to obtain higher quality: Ca.
The most reactive metals, such as sodium, will react with cold water to produce hydrogen and the metal hydroxide: 2 Na (s) + 2 H 2 O (l) →2 NaOH (aq) + H 2 (g) Metals in the middle of the reactivity series, such as iron , will react with acids such as sulfuric acid (but not water at normal temperatures) to give hydrogen and a metal salt ...
The stabilisation of ununennium's valence electron and thus the contraction of the 8s orbital cause its atomic radius to be lowered to 240 pm, [36]: 1729–1730 very close to that of rubidium (247 pm), [5] so that the chemistry of ununennium in the +1 oxidation state should be more similar to the chemistry of rubidium than to that of francium.
Why is francium so unstable? The article doesn't explain. Google found me a Prezi presentation (), but first off that's not a reliable source for expanding the francium article, and secondly it doesn't explain why many isotopes of related elements, e.g. 238 U with 54 more neutrons than protons, are so much longer lived.
I have noticed that the Francium article does not have a lead image of the pure sample like many other element pages. This is obviously because bulk francium has never been prepared. However, later in the article, it shows an image of light of 200,000 francium atoms and an image of heat from 300,000 francium atoms.