Since the invention of the periodic table 150 years ago this month, scientists have worked to fill in the rows of elements and make sense of their properties. But researchers have also pursued a ...

An atom is so small that a single drop of water contains more than a billion atoms. Although tiny, atoms are mostly empty space. The simplified model of the atom is that of a cloud of negative ...

SINCE our short account of the method of observing the Stark effect with a stabilised arc was written (see NATURE, March 31, p. 431), we have made experiments on about twenty different metals. With ...