A Markov chain is a discrete random process with the property that the next state depends only on the current state (wikipedia). A Markov chain is a discrete random process with the property that the next state depends only on the current state (wikipedia). So $P(X_n | X_1, X_2, \ldots X_n-1) = P(X_n | X_{n-1})$.
Some people find molecules and compounds confusing. Here's how to remember the difference. If you join two different chemical elements together, you can often make a completely new substance. Glue two atoms of hydrogen to an atom of oxygen and you'll make a single molecule of water.
A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atom s that are held together by chemical bonds.he atoms of certain elements readily bond with other atoms to form molecules. Examples of such elements are oxygen and chlorine. The atoms of some elements do not easily bond with other atoms.