Changes

==Composition of the atom==

==Composition of the atom==

Hydrogen [[atom]]s normally consist of a single [[proton]] and [[electron]], with no [[neutron]]. Other [[isotopes]] are formed as the atom gains neutrons: [[deuterium]] (one neutron) and [[tritium]] (two neutrons). Tritium is [[radioactive]].

Hydrogen [[atom]]s normally consist of a single [[proton]] and [[electron]], with no [[neutron]]. Other [[isotopes]] are formed as the atom gains neutrons: [[deuterium]] (one neutron) and [[tritium]] (two neutrons). Tritium is [[radioactive]], with a [[half-life]] of approximately 12 years.  

==Compounds==

==Compounds==

Hydrogen can be found in both [[organic]] and [[inorganic]] compounds.<ref>For example, [[hydrocarbon]]s and metal hydrides, respectively</ref> It is an important component of [[water]].

Hydrogen can be found in a vast majority of [[organic]] compounds, as well as some [[inorganic]] compounds.<ref>For example, [[hydrocarbon]]s and metal hydrides, respectively</ref> It is an important component of [[water]] and most [[acid]]s.  

==Fuel for vehicles==

==Fuel for vehicles==