Some atoms are unstable and will undergo radioactive decay. When this happens, they emit ionizing radiation are often transformed into another element. This article explains how to calculate rates of radioactive decay. Atoms which are prone to radioactive decay are known as radionuclides. Radionuclides can occur naturally, or can be man-made â such as during the fission process in a nuclear reactor.
Sir Francis Drake with his new heraldic achievement, with motto: Sic Parvis Magna, translated literally: Thus great things from small things (come). The hand out of the clouds is labelled Auxilio Divino, or With Divine Help.
mass, heap, early 15c., originally pillar, pier of a bridge, from Middle French pile and directly from Latin pila stone barrier, pillar, pier (see pillar). Sense development in Latin from pier, harbor wall of stones, to something heaped up.. In English, sense of heap of things is attested from mid-15c. (the verb in this sense is recorded from mid-14c.). The meaning large building (late 14c.) is probably the same word.