Search results
Results From The WOW.Com Content Network
It was only in 1960, when the metre was redefined in the same way, that the angstrom became again equal to 10 −10 metre. Yet the angstrom was never part of the SI system of units, [ 13 ] [ 14 ] and has been increasingly replaced by the nanometre ( 10 −9 m) or picometre ( 10 −12 m).
Because a dalton, a unit commonly used to measure atomic mass, is exactly 1/12 of the mass of a carbon-12 atom, this definition of the mole entailed that the mass of one mole of a compound or element in grams was numerically equal to the average mass of one molecule or atom of the substance in daltons, and that the number of daltons in a gram ...
The gigametre (SI symbol: Gm) is a unit of length in the metric system equal to 1 000 000 000 meters (10 9 m). To help compare different distances this section lists lengths starting at 10 9 meters (1 gigameter (Gm) or 1 billion meters). 1.2 Gm – separation between Saturn and Titan; 1.39 Gm – diameter of Sun [169] [170]
It is defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10 −34 when expressed in the unit J s, which is equal to kg m 2 s −1, where the metre and the second are defined in terms of c and ∆ν Cs." [1] The mass of one litre of water at the temperature of melting ice. A litre is one thousandth of a ...
In ordered solids, the atomic spacing between two bonded atoms is generally around a few ångströms (Å), which is on the order of 10 −10 meters (see Lattice constant). However, in very low density gases (for example, in outer space ) the average distance between atoms can be as large as a meter .
For example, the molecule acetylene has molecular formula C 2 H 2, but the simplest integer ratio of elements is CH. The molecular mass can be calculated from the chemical formula and is expressed in conventional atomic mass units equal to 1/12 of the mass of a neutral carbon-12 (12 C isotope) atom.
The ideal gas equation can be rearranged to give an expression for the molar volume of an ideal gas: = = Hence, for a given temperature and pressure, the molar volume is the same for all ideal gases and is based on the gas constant: R = 8.314 462 618 153 24 m 3 ⋅Pa⋅K −1 ⋅mol −1, or about 8.205 736 608 095 96 × 10 −5 m 3 ⋅atm⋅K ...
The picometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: pm) or picometer (American spelling) is a unit of length in the International System of Units (SI), equal to 1 × 10 −12 m, or one trillionth ( 1 / 1 000 000 000 000 ) of a metre, which is the SI base unit of length.