Methyl cation, anion, and radical. Methyl cation. The methylium cation (CH3+) exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the CH3+ cation, and this simplification is used pervasively in organic chemistry.
The square foot (plural square feet; abbreviated ft 2 or sq ft) is an imperial unit and U.S. customary unit (non-SI, non-metric) of area, used mainly in the United States and partially in Canada, United Kingdom, Hong Kong, Bangladesh, India and Pakistan. It is defined as the area of a square with sides of 1 foot.
A square foot is a unit of area in both US Customary Units as well as the Imperial System. The symbol for square foot is ft2 or sq ft. There are 43,560 square feet in an acre. A square foot is calculated as the area of a square that has 1 foot on each side.