The association of radiation and leukemia in humans has been clearly established in studies of victims of the Chernobyl nuclear reactor and atom bombs in Hiroshima and Nagasaki.

The fissioning of an atom of uranium-235 in the reactor of a nuclear power plant produces two to three neutrons, and these neutrons can be absorbed by uranium-238 to produce plutonium-239 and other isotopes.

When two monosaccharides undergo dehydration synthesis, water is produced, as two hydrogen atoms and one oxygen atom are lost from the two monosaccharides ' hydroxyl group.

For example, water is a compound containing hydrogen and oxygen in the ratio of two to one, with the oxygen atom between the two hydrogen atoms, and an angle of 104. 5 ° between them.

A carbohydrate is an organic compound that consists only of carbon, hydrogen, and oxygen, usually with a hydrogen: oxygen atom ratio of 2: 1 ( as in water ); in other words, with the empirical formula.

The bonds between the hydroxyl group, the hydrogen atom and their respective atoms break forming water from the hydroxyl and hydrogen, and the polymer.

This electrostatic potential map shows how the oxygen atom has a more negative charge ( red ) than the positive ( blue ) hydrogen atoms of a water molecule.

Representation of an organic compound | organic hydroxyl group, where R represents a hydrocarbon or other organic moiety, the red and grey spheres represent oxygen and hydrogen atoms, respectively, and the rod-like connections between these, covalent chemical bond s. A hydroxyl is a chemical functional group containing an oxygen atom connected by a covalent bond to a hydrogen atom, a pairing that can be simply understood as a substructure of the water molecule.

It possesses a regular crystalline structure based on the molecule of water, which consists of a single oxygen atom covalently bonded to two hydrogen atoms, or H-O-H.

Water is the chemical substance with chemical formula: one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom.

* Since the water molecule is not linear and the oxygen atom has a higher electronegativity than hydrogen atoms, it carries a slight negative charge, whereas the hydrogen atoms are slightly positive.

X-ray crystallography can locate every atom in a zeolite, an aluminosilicate with many important applications, such as water purification.

The free oxygen atom coordinates, freeing the newly formed water molecule and Fe ( IV )= O.

The negatively charged oxygen atom of one water molecule forms a hydrogen bond with a positively charged hydrogen atom in the other water molecule.

One characteristic is that it tastes different every time you try it, and scientists eventually discovered that one atom of bombastium dropped into a barrel of water becomes one barrel of ice cream-a different flavor of ice cream each time.

Meat cooked well done is brown because the iron atom is now in the + 3 oxidation state, having lost an electron, and is now coordinated by a water molecule.

Like other known molybdenum-containing oxidoreductases, the oxygen atom introduced to the substrate by XO originates from water rather than from dioxygen ( O < sub > 2 </ sub >).

In the next step the electrophilic carbon atom in the nitrilium ion is attacked by water and the proton is donated back to acetic acid.

In the transition state leading to the N-methyl acetimidic acid, the water oxygen atom is coordinated to 4 other atoms.

Upon entering, the water molecules face with their oxygen atom down the channel.

In simple valence bond theory the oxygen atom in water is sp < sup > 3 </ sup > hybridized with the lone pairs in equal sp < sup > 3 </ sup > orbitals.

For example, the creation of the hydronium ( H < sub > 3 </ sub > O < sup >+</ sup >) ion occurs when acids are dissolved in water and is due to the oxygen atom donating a lone pair to the hydrogen ion.

Here, so-called forced evaporative cooling is used to selectively remove high-energetic (" hot ") atoms from an atom cloud until the remaining cloud is cooled below the BEC transition temperature.

This complacency was blown to bits by the relativity of Einstein, the revelation of the complex anatomy of the atom and the discovery of the expanding universe.

Af was found to be paramagnetic with three unpaired electrons per chromium atom and a molecular susceptibility of Af, where Af.

Now this 1920 view of the atom was on the whole a discouraging picture.

and therefore the atom was really just a little machine ; ;

The SI second was defined in terms of the caesium atom in 1967, and in 1971 it was renamed International Atomic Time ( TAI ).

In 1911, Ernest Rutherford gave a model of the atom in which a central core held most of the atom's mass and a positive charge which, in units of the electron's charge, was to be approximately equal to half of the atom's atomic weight, expressed in numbers of hydrogen atoms.

Nevertheless, in spite of Rutherford's estimation that gold had a central charge of about 100 ( but was element Z = 79 on the periodic table ), a month after Rutherford's paper appeared, Antonius van den Broek first formally suggested that the central charge and number of electrons in an atom was exactly equal to its place in the periodic table ( also known as element number, atomic number, and symbolized Z ).

Moseley, after discussions with Bohr who was at the same lab ( and who had used Van den Broek's hypothesis in his Bohr model of the atom ), decided to test Van den Broek and Bohr's hypothesis directly, by seeing if spectral lines emitted from excited atoms fit the Bohr theory's demand that the frequency of the spectral lines be proportional to a measure of the square of Z.

The concept of an atom as an indivisible component of matter was first proposed by early Indian and Greek philosophers.

During the late 19th and early 20th centuries, physicists discovered subatomic components and structure inside the atom, thereby demonstrating that the ' atom ' was divisible.

Nevertheless, the basic idea of the atom was adopted by scientists thousands of years later because it elegantly explained new discoveries in the field of chemistry.

Rutherford interpreted the gold foil experiment as suggesting that the positive charge of a heavy gold atom and most of its mass was concentrated in a nucleus at the center of the atom — the Rutherford model.

Thus, the planetary model of the atom was discarded in favor of one that described atomic orbital zones around the nucleus where a given electron is most likely to be observed.

The Bohr model of the atom fixed the problem of energy loss from radiation from a ground state ( by declaring that there was no state below this ), and more importantly explained the origin of spectral lines.

The significance of the Bohr model was that it related the lines in emission and absorption spectra to the energy differences between the orbits that electrons could take around an atom.

With de Broglie's suggestion of the existence of electron matter waves in 1924, and for a short time before the full 1926 Schrödinger equation treatment of hydrogen like atom, a Bohr electron " wavelength " could be seen to be a function of its momentum, and thus a Bohr orbiting electron was seen to orbit in a circle at a multiple of its half-wavelength ( this historically incorrect Bohr model is still occasionally taught to students ).

In the quantum picture of Heisenberg, Schrödinger and others, the Bohr atom number n for each orbital became known as an n-sphere in a three dimensional atom and was pictured as the mean energy of the probability cloud of the electron's wave packet which surrounded the atom.

These energy levels depend on the type of atom and the chemical environment in which the atom was located.