|All helium isotopes have ____ protons.
|Carbon-14 has 6 protons and ____ neutrons.
|Uranium-238 is used to date ____ samples (rocks, meteorites).
|All carbon isotopes (e.g. C-12 and C-14) have ____ protons.
|Nuclei ____ during nuclear fission reactions.
|Tritium (two neutrons) is ____ than deuterium (one neutron).
|A ____ counter is used to detect ionizing radiation.
|An ____ particle consists of two protons and two neutrons.