Covalent interactions (bonds) hold atoms together within molecules. Covalent bonds are strong, with enthalpies are on the order of 100 kcal/mole (400 kjoule/mole). Covalent bonds break during chemical reactions, as during the burning of paper.
Public bodies reports. Public bodies 2014 provides a directory of data on non-departmental public bodies (. ), executive agencies and non-ministerial departments (NMDs), as well as summary information on the size and expenditure of these bodies and information on public appointments.
Inside the Torso. The body's functions are conducted by organs. Each organ is a recognizable structure (for example, the heart, lungs, liver, eyes, and stomach) that performs specific functions. An organ is made of several types of tissue and therefore several types of cells (see Cells).