Chemical element of metals. Cu comes from Cuprum, Fe comes from Ferrum, Ag from Argentum. The symbols were not followed by a period (full stop) as with abbreviations. Later chemical elements were also assigned unique chemical symbols, based on the name of the element, but not necessarily in English. For example, sodium has the chemical symbol 'Na' after the Latin "natrium". The same applies to "W" (wolfram) for tungsten, "Fe" (ferrum) for iron, "Hg" (hydrargyrum) for mercury, "Sn" (stannum) for tin, "K" (kalium) for potassium, "Au" (aurum) for gold, "Ag" (argentum) for silver, "Pb" (plumbum) for lead, "Cu" (cuprum) for copper, and
Chemical equation a 2 before O, giving the balanced equation: This equation does not have any coefficients in front of CH and CO, since a coefficient of 1 is dropped. Generally, any chemical equation involving "J" different molecules can be written as: where "R" is the symbol for the "j-th" molecule, and ν is the stoichiometric coefficient for the "j-th" molecule, positive for products, negative for reactants (or vice versa). A properly balanced chemical equation will then obey: where the composition matrix "a" is the number of atoms of element "i" in molecule "j". Any vector which, when operated upon by the