Yes, they are isotopes of helium
istopes have different numbers of neutrons and most of their elements have several istopes
Helium3's weight would be 3 grams!!!!!! Look on the periodic table if you don't believe me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
helium3
deuterium and tritium.
by their mass numbers.
istopes
neutrons
they have not been decided yet
istopes
neutrons
Examples: francium-223 or Fr-223.
Same number of protons; identical or very similar chemical properties.