Different atoms of the same element are called isotopes ... are used to date very ancient geological events that have to be measured in millions or billions of years.

Javier Sanchez-Yamagishi, a physicist who studies 2D materials at the University of California, Irvine, likens the ...

The ancient Greeks thought that there were just ... both of which are elements. All the atoms in a copper wire are the same. These are different to the atoms in aluminium foil which are all ...