On August 6, 1945, a 10-foot-long (3 meters) bomb fell from the sky over the Japanese city of Hiroshima.
Less than a minute later, everything within a mile of the bomb's detonation was obliterated.
A massive firestorm rapidly destroyed miles more, killing tens of thousands of people.
This was the first-ever use of an atomic bomb in warfare, and it used one famous element to wreak its havoc: uranium.
If, in the year AD 1600, you had asked an educated European how old the planet Earth was and to recount its history he would have said that it was about 6000 years old and that its ancient history was given by the biblical account in Genesis.
Thus Lithium-7 or Since different isotopes of an element all have the same number of protons and electrons, they have the same or similar chemical properties, but they differ in mass due to the different numbers of neutrons in the nucleus and because of this the nucleus may be unstable.In this period a number of comprehensive cosmogonies were proposed.These were long on armchair speculation and short on substantive supporting evidence.It is malleable, ductile, and slightly paramagnetic.Uranium metal has very high density , 65% more dense than lead , but slightly less dense than gold.