|a gadget; dingus; thingumbob.| |a chattering or flighty, light-
headed person.| isotope i·so·tope (ī'sə-tōp') One of two or more
atoms having the same atomic number but different mass numbers.
|isotope (ī'sə-tōp') Pronunciation Key One of two or more atoms
that have the same atomic number (the same number of protons)
but a different number of neutrons. Carbon 12, the most common
form of carbon, has six protons and six neutrons, whereas carbon
14 has six protons and eight neutrons. Isotopes of a given
element typically behave alike chemically. With the exception of
hydrogen, elements found on Earth generally have the same number
of protons and neutrons; heavier and lighter isotopes (with more
or fewer neutrons) are often unstable and undergo radioactive
decay. In physics, different forms of the same element, with
nuclei that have the same number of protons but different
numbers of neutrons. Isotopes are distinguished from each other
by giving the combined number of protons and neutrons in the
nucleus. For exam