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.
Hydrogen fuel is a zero-emission fuel when burned with oxygen (if one considers water not as an emission) or used in a contained cell also capable of 'reversing' the reaction if needed. It often uses electrochemical cells, or combustion in internal engines, to power vehicles and electric devices.