why did it take scientists nearly 80 years to discover francium when all the other alkalis were found in 1860?

Question

if you have proof on websites then that would really help

Answer 1

Francium is extremely rare ... it is much harder to discover something for which there is very little available to find.

the reasons that it is rare is that it is very unstable (it is radioactive and decays very quickly once it is formed ... the most stable isotope has a 1/2 life of only 22 minutes which means every 22 minutes only half of what you started with is left ... so after 44 minutes you only have 1/4 of the original amount and so on)

My guess is that the only naturally occuring Fr is the decay products or in the decay chain of other unstable elements such as U and Th, i.e. that it only exists because it is being continually produced. I would be a lot of what is known about it is from Fr produced artificially, i.e. with an accelerator though a nuclear reaction.

Answer 2

Francium is a radioactive element that occurs due to decay of other elements. I don't know its half-life, but it is apparently not enough for detectable amounts to be found in nature.