In the study of mineralogy, it is important to first understand the characteristics of an atom. Atoms are the smallest particles that still retain the characteristics of the elements on the periodic table. The nucleus, composed of protons and neutrons at the center of the atom, has a high mass and is surrounded by a much larger volume filled with electrons, which makes up the electron cloud.
In early models of the atom, electrons were shown to populate the cloud in orbitals or shells around the nucleus. The shells are defined by the quantum number n, which tells the number of electron shells in the cloud. This is the principal quantum number and describes the energy levels. Other quantum numbers are azimuthal quantum number, l, and the magnetic quantum number, m. The azimuthal number specifies the subshells that make up the orbitals. These subshells, determine the shape of the orbital. These subshells are referred to as s, p, d, f, etc., and are given a number, l, starting at 0 for subshell s. This then pairs with the magnetic quantum number. The number references the orbitaks within a subshell and restricts the orientation of each orbital. The interger values of m range from -l to +l.
Additionally, atoms of the same element can differ in the amount of neutrons they possess in the nucleus. These are called isotopes and while they do not affect the electrical charge of the atom, they do affect the mass. Different isotopes of elements are more common than others and some isotopes lead to radioactive decay, which can be used to date rocks or organic matter, depending on the element that is being used.
Recent comments