If play is stopped and the interference was by: 1  a team official, substitute, substituted or sent off player, play restarts with a direct free kick or penalty kick. 2  an outside agent, play restarts with a dropped ball.
Oxygen is one of the basic chemical elements. In its most common form, oxygen is a colorless gas found in air. It is one of the life-sustaining elements on Earth and is needed by all animals.Oxygen is also used in many industrial, commercial, medical, and scientific applications.hen oxygen is cooled below -297Â° F (-183Â° C), it becomes a pale blue liquid that is used as a rocket fuel. Oxygen is one of the most abundant chemical elements on Earth. About one-half of the earth's crust is made up of chemical compounds containing oxygen, and a fifth of our atmosphere is oxygen gas.
It is a colourless, odourless gas; pale blue liquid. Oxygen is extremely reactive and forms oxides with nearly all other elements except noble gases. It is the most abundant element in the earth's crust and makes up almost 21% of the atmosphere. Oxygen is obtained primarily from liquid air by fractional distillation. Small amounts are made in the laboratory by electrolysis of water. Oxygen is used in steel making, welding and supporting life.