Hydrogen (chemical symbol H) is a chemical element with atomic number 1. It has an atomic weight of 1.00794 u (or Da) (1.007825 u for the isotope1H containing no neutrons). It is the lightest and most abundant element, making up ~75% of the Universe’s detectable mass and ~90% of ...
Hydrogen, the most abundant substance in the universe, is also omnipresent on earth in the form of water, the most common liquid, following its name “hydro-gen”. Being the first element in the periodic table of elements, hydrogen can show extreme properties. It is the smallest and lightest...
Compound properties Element reactions List all H propertiesName: hydrogen Symbol: H Atomic number: 1 Relative atomic mass (Ar): 1.008 range: [1.00784, 1.00811] m [see notes g m r] Standard state: gas at 298 K Appearance: colourless Classification: Non-metallic Group in periodic table:...
Definition Hydrogen (chemical symbol H) is a chemical element with atomic number 1. It has an atomic weight of 1.00794 amu (1.007825 amu for the isotope 1 H containing no neutrons). It is the lightest and most abundant element, making up 75 % of the Universe's detectable mass and 90 %...
However, molecular hydrogen occurs in Nature in relatively small amounts and has to be produced from various sources, in which atomic hydrogen –it is the most abundant element – is combined with light elements such as carbon, nitrogen and oxygen. Therefore, the relative greenness of the ...
and in rocket fuels. Atomic number 1; atomic weight 1.00797; melting point -259.14=C; boiling point -252.8=C; density at 0=C 0.08987 gram per liter; valence 1.See table at element 氢：一种无色，易燃的气体物质，在所有气体中最轻，而宇宙中最多用来生产合成氨和甲醇，提炼石...
Hydrogen is a chemical element with the symbol H and atomic number 1 (strictly 1.008). It is the lightest element in the periodic table and the most abundant chemical substance in the Universe, constituting approximately 75% of all baryonic mass. The universal emergence ofatomic hydrogenfirst occ...
As the first element in the Periodic Table, hydrogen holds a special place in chemistry. When incorporated as a component of solid-state matter, the unique features of hydrogen are particularly striking. Its light mass is comparable to the effective electron mass of some heavy-Fermion solids; do...
Tritium, (T, or 3H), the isotope of hydrogen with atomic weight of approximately 3. Its nucleus, consisting of one proton and two neutrons, has triple the mass of the nucleus of ordinary hydrogen. Tritium is a radioactive species having a half-life of 12
With an atomic weight of 1.00794 u, hydrogen is the lightest element. Hydrogen is the most abundant chemical element, constituting roughly 75% of the universe's elemental mass. Stars in the main sequence are mainly composed of hydrogen in its plasma state. Elemental hydrogen is relatively rare ...