When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Chemical bond - Wikipedia

    en.wikipedia.org/wiki/Chemical_bond

    A single bond between two atoms corresponds to the sharing of one pair of electrons. The Hydrogen (H) atom has one valence electron. Two Hydrogen atoms can then form a molecule, held together by the shared pair of electrons. Each H atom now has the noble gas electron configuration of helium (He).

  3. Hydrogen bond - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_bond

    An ubiquitous example of a hydrogen bond is found between water molecules. In a discrete water molecule, there are two hydrogen atoms and one oxygen atom. The simplest case is a pair of water molecules with one hydrogen bond between them, which is called the water dimer and is often used as a model system. When more molecules are present, as is ...

  4. Nuclear binding energy - Wikipedia

    en.wikipedia.org/wiki/Nuclear_binding_energy

    The most common isotope of helium contains two protons and two neutrons, and those of carbon, nitrogen and oxygen – six, seven and eight of each particle, respectively. However, a helium nucleus weighs less than the sum of the weights of the two heavy hydrogen nuclei which combine to make it. [6] The same is true for carbon, nitrogen and oxygen.

  5. Nucleic acid structure - Wikipedia

    en.wikipedia.org/wiki/Nucleic_acid_structure

    The linking number for circular DNA can only be changed by breaking of a covalent bond in one of the two strands. Always an integer, the linking number of a cccDNA is the sum of two components: twists (Tw) and writhes (Wr). [16] = + Twists are the number of times the two strands of DNA are twisted around each other.

  6. Hyperfine structure - Wikipedia

    en.wikipedia.org/wiki/Hyperfine_structure

    Here, the electric quadrupole interaction is due to the 14 N-nucleus, the hyperfine nuclear spin-spin splitting is from the magnetic coupling between nitrogen, 14 N (I N = 1), and hydrogen, 1 H (I H = 1 ⁄ 2), and a hydrogen spin-rotation interaction due to the 1 H-nucleus. These contributing interactions to the hyperfine structure in the ...

  7. Hydrogen atom - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_atom

    Depiction of a hydrogen atom showing the diameter as about twice the Bohr model radius. (Image not to scale) A hydrogen atom is an atom of the chemical element hydrogen.The electrically neutral hydrogen atom contains a single positively charged proton in the nucleus, and a single negatively charged electron bound to the nucleus by the Coulomb force.

  8. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    A chemical bond between valence electrons, or an atom or unbranched chain of atoms connecting two different parts of the same molecule; i.e. an intramolecular bond linking different moieties or functional groups. [2] bridgehead Either of the two tertiary atoms which by bonding to each other form an intramolecular bridge. [2] Brønsted–Lowry acid

  9. Base pair - Wikipedia

    en.wikipedia.org/wiki/Base_pair

    The GU pairing, with two hydrogen bonds, does occur fairly often in RNA (see wobble base pair). Paired DNA and RNA molecules are comparatively stable at room temperature, but the two nucleotide strands will separate above a melting point that is determined by the length of the molecules, the extent of mispairing (if any), and the GC content.