"atom", "the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical attraction"
"atomic configuration", "the relative disposition or arrangement of the parts or elements of an atom"
"atomic theory", "Physics, Chemistry. any of several theories describing the structure, behavior, and other properties of the atom and its component parts."
"attract", "to draw by a physical force causing or tending to cause to approach, adhere, or unite; pull"
"axis", "a central or principal structure, about which something turns or is arranged"
"balance", "a state of equilibrium or equipoise; equal distribution of weight, amount"
"base", "the bottom support of anything; that on which a thing stands or rests"
"Big Bang Theory", "a theory that deduces a cataclysmic birth of the universe (big bang)from the observed expansion of the universe, cosmic background radiation, abundance of the elements, and the laws of physics"
"biodiversity", "diversity among and within plant and animal species in an environment"
"biotic", "pertaining to life"
"bird", "an animal having a body covered with feathers, forelimbs modified into wings, scaly legs, a beak, and no teeth, and bearing young in a hard-shelled egg"
"calorie", "an amount of heat exactly equal to 4.1840 joules"