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.
An atom consists of a nucleus made of protons and neutrons in addition to electrons that orbit the nucleus. Since electrons are never in a fixed position, the position of the outermost electron is uncertain, and this makes determining the atomic radius difficult.