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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 ...
Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...
A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond. A saturated fat has no carbon-to-carbon double bonds, so the maximum possible number of hydrogen is bonded to carbon, and thus, is considered to be "saturated" with hydrogen atoms.
Disaccharides are formed when two monosaccharides, or two single simple sugars, form a bond with removal of water. They can be hydrolyzed to yield their saccharin building blocks by boiling with dilute acid or reacting them with appropriate enzymes. [6] Examples of disaccharides include sucrose, maltose, and lactose.
The double bonds in unsaturated fats can be converted into single bonds by reaction with hydrogen effected by a catalyst. This process, called hydrogenation , is used to turn vegetable oils into solid or semisolid vegetable fats like margarine , which can substitute for tallow and butter and (unlike unsaturated fats) resist rancidification .
By some definitions, "organic" compounds are only required to contain carbon. However, most of them also contain hydrogen, and because it is the carbon-hydrogen bond that gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. [12]
Hydrogen forms hydrogen bonds with three elements which are nitrogen (N), oxygen (O) and fluorine (F). The names of these elements can be remembered by the following mnemonic. The names of these elements can be remembered by the following mnemonic.
Although hydrogen bonding is a relatively weak attraction compared to the covalent bonds within the water molecule itself, it is responsible for several of the water's physical properties. These properties include its relatively high melting and boiling point temperatures: more energy is required to break the hydrogen bonds between water molecules.