Callahan County, TX Real Estate & Homes for Sale Homes for Sale in Callahan County, TX have a median listing price of $128,995 and a price per square foot of $75. There are 103 active homes for sale in Callahan County, Texas, which spend an average of 73 days on the market. Some of the hottest neighborhoods near Callahan County, TX are Tanglewood East, Chimney Rock Area, Far Southside, River Oaks-Brookhollow. You may also be interested in homes for sale in popular zip codes like 79602, 79601, or in neighboring cities, such as Abilene, Clyde, Baird, Cisco, Coleman.
hydrogen bond. A chemical bond in which a hydrogen atom that is already bonded to an atom in a molecule forms a second bond with another atom, either in the same molecule or in a different one. The second atom is usually of a type that strongly attracts electrons, such as nitrogen or oxygen.
1 This attraction forms weak bonds between molecules. 2  When hydrogen is one of the atoms within a molecule that is attracted to the dipole on another molecule, this somewhat stronger dipole-dipole attraction is called a hydrogen bond. The hydrogen bond is the attraction between molecules, not the covalent bond which is formed between hydrogen and an atom from its own molecule. 2  Below are some examples of hydrogen bonding. 3  Click on the image below to see hydrogen bonds represented as dotted lines in this computer model.