Report Abuse. X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 Ã 1016 Hz to 3 Ã 1019 Hz) and energies in the range 120 eV to 120 keV.hen x-rays were first discovered, scientists didn't know much about them, so they called them X-rays because X in science is often used to designate an unknown as in Planet X or solve for X They were also sometimes called Rontgen Rays after the man who discovered them.
1. calcium ion-ion of calcium; a factor in the clotting of blood. factor IV. atomic number 20, Ca, calcium-a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals.. calcium ion-ion of calcium; a factor in the clotting of blood. factor IV. atomic number 20, Ca, calcium-a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals.
Full Definition of CALCIUM. : a silver-white divalent metallic element of the alkaline-earth group occurring only in combination â see element table. See calcium defined for English-language learners. See calcium defined for kids.ADVERTISEMENT.ull Definition of CALCIUM. : a silver-white divalent metallic element of the alkaline-earth group occurring only in combination â see element table. See calcium defined for English-language learners. See calcium defined for kids.