Answer: hydrogen

AnswerCrossword Clue
HYDROGENTypical univalent element.
hydrogena gaseous element
hydrogenA colorless, odorless, highly flammable gas, the chemical element of atomic number 1
HYDROGENFirst item on a certain table
HYDROGENOne on a certain table
HYDROGENLightest known substance
HYDROGENLightest of all known substances.
HYDROGENThe lightest of all known substances.
HYDROGENElement potentially destructive.
HYDROGENElement of vast power.
HYDROGENIt's always number one
HYDROGENFocus of scientific limelight.
HYDROGENLightest element
HYDROGENLight element
HYDROGENRocket fuel component
HYDROGENLight gas
HYDROGENElement in water
HYDROGENMost abundant element
HYDROGENH