The Bohr Model (Niels Bohr) In 1913, Niels Bohr came up with a new model (Bohr was a student of Rutherford) He noticed that light given out when atoms were heated always had specific amounts of energy, so Niels Bohr proposed a model that electrons in an atom must be orbiting the nucleus and can reside only in fixed energy levels
Energy Levels • Each of the electrons in Bohr’s model has a fixed amount of energy called energy levels • This is similar to steps of a ladder (can climb up the ladder, but cannot step in between the steps) • Quantum is the amount of energy required to move an electron from one energy level to another • The further away from the nucleus, the more energy the electron has
The Quantum Mechanics Model (Erwin Schrodinger) • While Rutherford’s model described the path the electron moves, Erwin Schrodinger solved mathematical equations to describe the behavior of electron • Similar to Bohr’s model, Schrodinger describes the energy of electrons with certain values but does not involve an exact path the electron takes around the nucleus
The Quantum Mechanics View of the Atom (Schrodinger) The quantum mechanical model does not describe the exact path an electron takes around the nucleus, but determines the probability of finding an electron in a certain area
Quantum Mechanical Model • In this model, electrons move similar to a rotating propeller blade • You cannot tell its precise location at any instant because it’s a blurry region, but you have information regarding the probability of finding an electron within a certain volume of space • Similar to a fuzzy cloud…the probability of finding an electron is higher where the cloud is more dense
Atomic Orbitals A region of space where electrons are likely to be located. Each energy level can be made up of sublevels, which is made of different orbitals
Draw an s orbital. Now draw a 2s orbital. How are they different?
Draw three p orbitals. Now, draw all three p orbitals on an x-y-z axis