Radial: A word with diverse meanings in medicine and the biomedical sciences: 1  Pertaining to the radius, the smaller bone in the forearm. 2  The radial artery is so named because of its proximity to the radius. 3  Pertaining to the radius of a circle.
A 3D model of ethyne (acetylene), the simplest alkyne. In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbonâcarbon triple bond. The simplest acyclic alkynes with only one triple bond and no other functional groups form a homologous series with the general chemical formula CnH2nâ2.
Of these, the question of which planet is the smallest has been the subject of some controversy. Until recently, the smallest planet was considered to be Pluto. But with the 2006 IAU Resolution that put constraints on what the definition of a planet entails, that status has since passed to Mercury. So in addition to being the closest planet to the Sun, Mercury is also the smallest. Size and Mass: With a mean radius of 2440 km, Mercury is the smallest planet in our Solar System, equivalent in size to 0.38 Earths. And given that it has its experiences no flattening at the poles â like Venus, which means it is an almost perfectly spherical body â its radius is the same at the poles as it is the equator.