radon radon rn chemical element a heavy radioactive gas of group 18 noble gases of the periodic table generated by the radioactive decay of radium radon was originally called radium emanation radon is a colourless gas 75 times heavier than air.
isotope vs nuclide a nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus for example carbon13 with 6 protons and 7 neutrons the nuclide concept referring to individual nuclear species emphasizes nuclear properties over chemical properties whereas the isotope concept grouping all atoms of each element emphasizes chemical over nuclear.
A radioactive element is one with an unstable nucleus which radiates alpha beta or gamma radiation and gets converted to a stable element this article has a comprehensive list of radioactive elements and their properties.
chemical element also called element any substance that cannot be decomposed into simpler substances by ordinary chemical processeselements are the fundamental materials of which all matter is composed this article considers the origin of the elements and.
The periodic table of the elements the periodic table is an arrangment of the chemical elements ordered by atomic number so that periodic properties of the.
Notes the site still exists but many of the pages seem to be no longer maintained and available and i have not been able to reach the original site developer robert monaghan who collected and edited the following information from use net postings.
Span classnews_dtmar 17 2010spannbsp018332i have this one little saying when things get too heavy just call me helium the lightest known gas to man jimi hendrix hendrix is almost right helium.
Heroes and villains a little light reading here you will find a brief history of technology initially inspired by the development of batteries it covers technology in general and includes some interesting little known or long forgotten facts as well as a few myths about the development of technology the science behind it the context in which it occurred and the deeds of the many.
A further example from a lava flow off the coast of hawaii shows similar discrepancies if dated with the carbon14 method the flow appears to be less than 17000 years old but dating with the potassium argon method gives dates of 160000 to 43 million years.