Chemical formula that compound will be made up of the same elements in the same proportion or ratio. For example, any water molecule is always made up of two hydrogen atoms and one oxygen atom in a 2:1 ratio. If we look at the relative masses of oxygen and hydrogen in a water molecule, we see that 94% of the mass of a water molecule is accounted for by oxygen and the remaining 6% is the mass of hydrogen. This mass proportion will be the same for any water molecule. The alkene called but-2-ene has two isomers, which the chemical formula CHCH=CHCH
Landauer formula nanoscale conductor is given by the sum of all the transmission possibilities that an electron has when propagating with an energy equal to the chemical potential, formula_5. A generalization of the Landauer formula for multiple probes is the Landauer-Büttiker formula, proposed by Landauer and . If probe formula_6 has voltage formula_7 (that is, its chemical potential is formula_8), and formula_9 is the sum of transmission probabilities from probe formula_10 to probe formula_6 (note that formula_9 may or may not equal formula_13), the net current leaving probe formula_14 is Landauer formula The Landauer formula—named after Rolf Landauer, who first suggested its