noun. A mixture of butter and suger. A mixture of butter and suger. The definition of a mixture is a combination of different things, or the state or act of being mixed. 1  An example of a mixture is a bowl of butter, sugar and salt. 2  An example of mixture is the process of combining flour and baking soda.
deuterium oxide. An isotope of water in which hydrogen has been displaced by its isotope deuterium. Its properties differ from ordinary water in that it has higher freezing and boiling points and is incapable of supporting life.
Hydrogen is unique in that it has three isotopes which are named. Deuterium is one of the isotopes of hydrogen. It has one proton and one neutron. The most common isotope of hydrogen is protium, which has one proton and no neutrons.Because deuterium contains a neutron, it is more massive or heavier than protium, so it is sometimes called heavy hydrogen.By Anne Marie Helmenstine, Ph.D. Deuterium is a stable isotope of hydrogen. 2  The natural abundance of deuterium in the ocean is approximately 156.25 ppm, which is one atom in 6,400 of hydrogen. 3  The name for deuterium comes from the Greek word deuteros, which means second.