it is also the lightest element isotopes are atoms of the same element with different numbers of neutrons in ancient times the elements referred to fire earth water and air helium is the second most common element in the universe but is very rare on the earth
Featherweight is a weight class in the combat sports of boxing, kickboxing, mixed martial arts and Greco-Roman wrestling.
a synovial joint in which the rounded or spheroidal surface of one bone ('ball') moves within a cup-shaped depression ('socket') on another bone, allowing greater freedom of movement than any other type of joint. Called also spheroidal joint. synovial joint that allows movement in only one plane, through the presence of a pair of collateral ligaments that run on either side of the joint. Examples are the elbow and the interphalangeal joints of the digits. The jaw is primarily a hinge joint, but it can also move somewhat from side to side.