Chemical substance made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt (sodium chloride) and refined sugar (sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical. Chemical substances exist as solids, liquids, gases, or plasma, and may change between these phases of matter with changes in temperature or pressure. Chemical substances may be combined or converted to others by means of chemical reactions. Forms of energy, such as light and heat, are not matter, and are thus not "substances" in this
Inclusion compound is known as a clathrate, not an inclusion complex. In molecular encapsulation, a guest molecule is trapped inside another molecule. Inclusion compound In host-guest chemistry, an inclusion compound is a complex in which one chemical compound (the "host") has a cavity into which "guest" compound can be accommodated. The interaction between the host and guest involves purely van der Waals bonding. The definition of inclusion compounds is very broad, extending to channels formed between molecules in a crystal lattice in which guest molecules can fit. Calixarenes and related formaldehyde-arene condensates are one class of hosts that form inclusion compounds. One