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.
Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft gray alkaline earth metal, fifth-most-abundant element by mass in the Earth 's crust. The ion Ca 2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.alcium is essential for living organisms, in particular in cell physiology, where movement of the calcium ion into and out of the cytoplasm functions as a signal for many cellular processes.