Emotions are therefore accompanied by biochemical changes in the brain. Fear is accompanied by the production of brain chemicals that cause alertness and readiness to flee; pleasure triggers the release of "feel-good" brain chemicals. Long-term production of stress hormones can damage the hippocampus (the part of the brain central to learning and memory) and experiments show that stressed-out mothers have more problems producing healthy offspring. Other emotions are not so biologically clear-cut, for example "shame" and "embarrassment" are "social emotions" - the result of attaching emotional meanings to, respectively, unacceptable or inappropriate behaviours. While emotions such as fear and pleasure are common to humans and animals, researchers cannot agree on how great a role social emotions play in non-human animals.
A covalent bond is the chemical bonding in which the attractive force between atoms is created by the sharing of electrons, resulting in the formation of a cell's molecules and is categorized into two subtypes, non-polar and polar....
Chemical bonds are interactions of electrons between atoms
Chemical Engine No. 3, stands in front of the Bridge St. House, which was located on E. Bridge St. (now Michigan) at the junction of Kent St. (became Bond in 1912). Four firemen in their helmets stand around the machine, and a couple of bystanders look on.