The most obvious piece of equipment a receptionist uses is a telephone, but there is a lot of variety in types and styles, from phone systems with a few lines to switchboards with multiple lines.
Modern Atomic Theory Bohr's model of the atom is important because it introduced the concept of the quantum in explaining atomic properties. However, Bohr's model ultimately needed revision becuase it failed to explain the natue of atoms more complicated than hydrogen.rwin Schrodinger developed the equation which is used today to understand atoms and molecules-the Schrodinger Equation (1926) Erwin Schrodinger took the ideas developed by de Broglie, Heisenberg and others and put them together in a single equation that is named after him.
A typical atom consists of three subatomic particles: protons, neutrons, and electrons (as seen in the helium atom below). Other particles exist as well, such as alpha and beta particles (which are discussed below). The Bohr model shows the three basic subatomic particles in a simple manner. Most of an atom's mass is in the nucleusâa small, dense area at the center of every atom, composed of nucleons. Nucleons include protons and neutrons. All the positive charge of an atom is contained in the nucleus, and originates from the protons. Neutrons are neutrally-charged.