In heavy water, each hydrogen atom is indeed heavier, with a neutron as well as a proton in its nucleus. This isotope of hydrogen is called deuterium, and heavy water's more scientific name is ...

All three isotopes of hydrogen have identical chemical properties. This is because the number of electrons determines chemical properties, and all three isotopes have one electron in their atoms.

as part of the Hydrogen Isotopes 1,2,3H Research Training Group, has made an important breakthrough in the efficient and cost-effective provision of isotopes. These are the three forms in which ...

While the number of protons defines the element (e.g., hydrogen, carbon, etc.) and the sum of the protons and neutrons gives the atomic mass, the number of neutrons defines the isotope of that element ...

An element's atomic number defines it. An element with 17 protons will always be chlorine. However an element's mass numbers can vary, which means that it can have different numbers of neutrons.