The maximum dimensions for your carry-on bag are: Length - 24 (61cm) including wheels and handles ; Width - 17 (43cm) Height - 10 (25cm) For additional carry-on items beyond the one-bag limit, each piece will incur a fee. Refer to the checked baggage page for more information.
Tritium (3H) is the most stable radioisotope of hydrogen. That is, of all radioactive isotopes of hydrogen, tritium is the least radioactive. It has a proton and 2 neutrons in its nucleus. Tritium decays through beta minus decay and changes to helium-3. It has a half-life of 12.32 years.
This is called the half-life of the radioactive isotope. There are two definitions of half-life, but they mean essentially the same thing. Different radioactive isotopes have different half-lives. For example, the half-life of carbon-14 is 5,715 years, but the half-life of francium-223 is just 20 minutes.