Why do the atomic weights on the periodic table keep changing? Kit Chapman meets the team behind the decimal places ...

Last year, the International Union of Pure and Applied Chemistry (Iupac) revised the atomic weights of gadolinium, lutetium ...

Mendeleev's ideas are still in use today. However, the modern periodic table arranges the elements by increasing atomic number, rather than atomic mass. Dmitri Mendeleev ...

GCSE Combined Science Atomic structure and the periodic table learning resources for adults, children, parents and teachers.

Magnesium’s atomic weight, meanwhile, was formerly 24.3050, but is now represented by the interval [24.304, 24.307]. More to come ...