Iridium, a precious metal belonging to the platinum group of elements, is more abundant in meteorites than in terrestrial rocks.
Again, the first numeral indicates the major alloying element or group of elements.
(Sulfur, S, and selenium, Se, belong to the group of elements called chalcogens).
Mendeleyev did not realise it, but there was a group of elements missing from his periodic table.
A precious metal belonging to the platinum group of elements, iridium is more abundant in meteorites than in rocks on Earth.
These are commonly manufactured using metals from the very high risk platinum group of elements which are produced principally in South Africa and Russia.
As is true of the lightest element in each group of elements, the physical properties of carbon differ substantially from those of the other members of its family.
Electron-spin resonance (ESR) was first observed in 1944 by a Soviet physicist, Y.K. Zavoysky, in experiments on salts of the iron group of elements.
It appears that the first group of elements must be manufactured together, presumably in massive stars, and ejected together into the interstellar gas.
GUYUN VILLAGE, China — Some of the greenest technologies of the age, from electric cars to efficient light bulbs to very large wind turbines, are made possible by an unusual group of elements called rare earths.
Such defects, called aberrations, can be eliminated and even then not completely only by replacing the single lens element by a group of elements of appropriate shape and separation.
