These different forms are called isotopes, meaning some oxygen atoms are lighter and some are heavier. At lower water temperatures, a higher abundance of the heavy oxygen isotope is incorporated ...

These different forms are called isotopes, meaning some oxygen atoms are lighter and some are heavier. At lower water temperatures, a higher abundance of the heavy oxygen isotope is incorporated ...

Isotopes can be stable, meaning they keep their atomic configuration, or unstable, meaning they decay and break down into other elements by gaining or shedding protons.

Most nitrogen comes as the isotope nitrogen-14, with seven protons and seven neutrons. But physicists say they have glimpsed a far more elusive variant with just two neutrons.