Tritium is an isotope of

Which of the following statements concerning protium,deuterium and tritium is not true?

Which of the following is $NOT$ true regarding the usage of hydrogen as a fuel?

Which of the following statements is not true for hydrogen:
$1)$ It exists as a diatomic molecule.
$2)$ It has one electron in the outermost shell.
$3)$ It can lose an electron to form a cation which can freely exist.
$4)$ It cannot form ionic compounds.

The number of hydrogen molecules possible from its isotopes is

The reaction of $H_2S$ with $O_2$ produces .....