| the 22nd letter of the Roman alphabet | a unit of potential equal to one quadrillionth of a volt (or one thousandth of a picovolt) |
| a unit of potential equal to the potential difference between two points on a conductor carrying a current of 1 ampere when the power dissipated between the two points is 1 watt; equivalent to the potential difference across a resistance of 1 ohm when 1 ampere of current flows through it | |
| the cardinal number that is the sum of four and one | |
| a soft silvery white toxic metallic element used in steel alloys; it occurs in several complex minerals including carnotite and vanadinite | |