The first financial model to use a Markov chain was from Prasad et al. in 1974. Another was the regime-switching model of James D. Hamilton (1989), in which a Markov chain is used to model switches between periods of high volatility and low volatility of asset returns.
A molecule is a particle containing two or more atoms. If it contains only one type of atom it is called an element.
A molecule is what you get when any atoms join together. A compound is what you get when atoms of two or more different elements join together. All compounds are molecules, but not all molecules are compounds. Water is a molecule because it is made from atoms that have been chemically combined. It is also a compound because the atoms that make water are not all the same-some are oxygen and some are hydrogen. Oxygen in the atmosphere is a molecule because it is made from two atoms of oxygen. It is not a compound because it is made from atoms of only one element-oxygen. This type of molecule is called a diatomic molecule, a molecule made from two atoms of the same type.