Technetium, with atomic number denoted Z43, is the lowest-numbered element in the periodic table of which all isotopes are radioactive
Concentration Definition. In chemistry, concentration refers to the amount of a substance per defined space. Another definition is that concentration is the ratio of solute in a solution to either solvent or total solution. Concentration usually is expressed in terms of mass per unit volume.
An oxidation-reduction (redox<span>) </span>reaction<span> is a type of chemical </span>reaction<span> that involves a transfer of electrons between two species. An oxidation-reduction </span>reaction<span> is any chemical </span>reaction<span> in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.</span>