* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 5 Electrons in Atoms
Bohr–Einstein debates wikipedia , lookup
Molecular Hamiltonian wikipedia , lookup
Particle in a box wikipedia , lookup
X-ray fluorescence wikipedia , lookup
James Franck wikipedia , lookup
Chemical bond wikipedia , lookup
Molecular orbital wikipedia , lookup
Wave–particle duality wikipedia , lookup
Theoretical and experimental justification for the Schrödinger equation wikipedia , lookup
Rutherford backscattering spectrometry wikipedia , lookup
X-ray photoelectron spectroscopy wikipedia , lookup
Auger electron spectroscopy wikipedia , lookup
Quantum electrodynamics wikipedia , lookup
Electron scattering wikipedia , lookup
Electron-beam lithography wikipedia , lookup
Hydrogen atom wikipedia , lookup
Tight binding wikipedia , lookup
Atomic orbital wikipedia , lookup
Electron configuration wikipedia , lookup
“Electrons in Atoms” Turn to Page 11 in your Standards Book Electrons in Atoms Section 5.1 Models of the Atom OBJECTIVES: • Identify the inadequacies in the Rutherford atomic model. Section 5.1 Models of the Atom OBJECTIVES: • Identify the new proposal of the Bohr model of the atom. Section 5.1 Models of the Atom OBJECTIVES: • Describe the energies and positions of electrons according to the quantum mechanical model. Section 5.1 Models of the Atom OBJECTIVES: • Describe how the shapes of orbitals related to different sublevels differ. Ernest Rutherford’s Model Discovered dense positive piece at the center of the atom- “nucleus” Electrons would surround and move around it, like planets around the sun Atom is mostly empty space It did not explain the chemical properties of the elements – a better description of the electron behavior was needed Atomic Models Part 1 Niels Bohr’s Model Why don’t the electrons fall into the nucleus? Move like planets around the sun. Bohr proposed that an electron is found only in specific circular paths, or orbits, around the nucleus. An amount of fixed energy separates one level from another. The Bohr Model of the Atom I pictured the electrons orbiting the nucleus much like planets orbiting the sun. Niels Bohr However, electrons are found in specific circular paths around the nucleus, and can jump from one level to another. Bohr’s model Each possible electron orbit in Bohr’s model has a fixed energy. The fixed energies an electron can have are called energy levels. • analogous to the rungs of a ladder A quantum of energy is the amount of energy required to move an electron from one energy level to another • The electron cannot exist between energy levels, just like you can’t stand between rungs on a ladder The Quantum Mechanical Model In 1926, Erwin Schrodinger derived an equation that described the energy and position of the electrons in an atom Schrodinger’s Wave Equation d V 8 m dx h 2 2 Erwin Erwin Schrodinger Schrodinger 2 2 E Equation for the probability of a single electron being found along a single axis (x-axis) The Quantum Mechanical Model Things that are very small behave differently from things big enough to see. The quantum mechanical model is a mathematical solution It is not like anything you can see (like plum pudding!) The Quantum Mechanical Model Has energy levels for electrons. Orbits are not circular. It can only tell us the probability of finding an electron a certain distance from the nucleus. The Quantum Mechanical Model The electron is found inside a blurry “electron cloud” An area where there is a chance of finding an electron. Think of fan blades The propeller blade has the same probability of being anywhere in the blurry region, but you cannot tell its location at any instant. The electron cloud of an atom can be compared to a spinning airplane propeller. Atomic Models Part 2 Atomic Orbitals An atomic orbital is a 3 dimensional region of space in which there is a high probability of finding an electron. Orbitals Shapes Different atomic orbitals are denoted by letters. The s orbitals are spherical, and p orbitals are dumbbell-shaped. The # in front indicates the energy level of the electron ie 1s, 2s Four of the five d orbitals have the same shape but different orientations in space.