Answer:
Hydrogen gas
Explanation:
During electrolysis of acidified water, H+ ions are reduced to H2 gas at the negative carbon electrode (cathode) and hence hydrogen gas is liberated at cathode.
Hydrogen H weight: 81
Non-metal
Hydrogen is the simplest element; an atom consists of only one proton and one electron. It is also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth--it is always combined with other elements.
period 1 group 1
Hydrogen is easily the most abundant element in the universe. It is found in the sun and most of the stars, and the planet Jupiter is composed mostly of hydrogen. On Earth, hydrogen is found in the greatest quantities as water.
