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.
Introduction. In its elemental state, Oxygen is a colorless, odorless, diatomic gas with chemical formula O 2 and will often act as an oxidizing agent. Lewis structure of the. Oxygen gas molecule. Oxygen gas makes up about 20% of the Earth's atmosphere. Higher concentrations of Oxygen gas increase the risk of fire and the combustion of flammable substances. One should keep this in mind and take appropriate safety precautions when working in an Oxygen-rich atmosphere.