WordNet
n. an atom of hydrogen
Wikipedia
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the elemental ( baryonic) mass of the universe.
In everyday life on Earth, isolated hydrogen atoms (usually called "atomic hydrogen" or, more precisely, "monatomic hydrogen") are extremely rare. Instead, hydrogen tends to combine with other atoms in compounds, or with itself to form ordinary ( diatomic) hydrogen gas, H. "Atomic hydrogen" and "hydrogen atom" in ordinary English use have overlapping, yet distinct, meanings. For example, a water molecule contains two hydrogen atoms, but does not contain atomic hydrogen (which would refer to isolated hydrogen atoms).
Attempts to develop a theoretical understanding of the hydrogen atom have been important to the history of quantum mechanics.
Usage examples of "hydrogen atom".
If you add a neutron - that has no electrical charge - to the hydrogen atom, you get deuterium.
This means that two bonds still remain and each of these can be attached to a hydrogen atom.
A hydrogen atom has a proton with positive charge as nucleus, surrounded by an electron with negative charge.
The blue light he was seeing came from the brightest line produced by the hydrogen atom when it gets excited.
At top left is a schematic representation of the hyperfine transition between parallel and antiparallel proton and electron spins of the neutral hydrogen atom.
In such a case, each electron (there is only one in each hydrogen atom) contributes to the bond, and there are no neutrons to add wasted mass.
A hydrogen atom, in a suitable context, can remain a hydrogen atom.
They asserted that the expansion of the universe and the redshift could be explained if it were assumed that single atoms of hydrogen were somehow coming into being constantly in the depths of spaceperhaps about one hydrogen atom per year in a volume of space equal to that of the Great Mosque.
Tritium is useful because the hydrogen atom is not supposed to contain any neutrons at all, much less two of them.
The wavelength of the hydrogen atom in spectrum analysis (which radiates symbolically from the sun on the plaque with a line 20.
It's spread out thin and uniform: on average there's one hydrogen atom in a space the size of one of our transport pods.
Matter is simply ether in motion, is composed of corpuscles, electrically charged ions, or electrons, moving units of negative electricity about one one-thousandth part of the hydrogen atom.
We know very little about this stuff other than the fact that it can affect the hydrogen atom in strange ways.
The one that attracted the most interest was its ability to change the hydrogen atom in subtle ways.
But according to the immutable laws of physics, one hydrogen atom is absolutely identical to every other hydrogen atom and can be treated in exactly the same way.