For the first time those little numbers that appear beneath some of the commonest elements in the periodic table boxes are about to change from a single value to an interval of numbers An ...

Law Of Conservation Of Mass: Did you know that in water the ratio of the mass of hydrogen to the mass of oxygen is always 1:8? This led to one of the laws of chemical combination, the law of constant ...

How does one go about measuring the mass of an object? Mass is defined as the amount of matter an object contains. This is very different from weight, of course, as the mass of our object would remain ...

Thank you for bringing to my attention the recent International Union of Pure & Applied Chemistry report “Atomic weights of the elements 2009” (C&EN, Dec. 20 ...

We are shown that the atomic number is the number of protons in an atom. We see that the mass number minus the atomic number is the number of neutrons. We complete the atomic structure by explaining ...