Chapter 5: Electrons in Atoms 3 major subatomic particles? ProtonElectronNeutron What is the charge on each? Which identifies the atom? Which tells the chemical properties? structure of the atom? 1) Small, dense nucleus. 2) Nucleus is neutrons & protons. 3) Nucleus has a positive charge. 4) 4) Most mass is found in the nucleus 5) Electrons surround the nucleus and occupy most of the volume Evolution of 3 Atomic Models John Dalton (1766 1844) : atomic theory J.J. Thomson (1856 1940) : electron 3. Ernest Rutherford (1871 1937) : nucleus Arent they cute!! didnt tell of electron. didnt tell locations & energy of electron Bohr Planetary Model electrons orbit the nucleus Bohr asked What prevents the electrons from falling into the nucleus? w/ fixed amount of energy, fixed path & wont fall inward Niels Bohr (1885 1962) electrons exist in energy levels around nucleus Young Bohr Old Bohr Wild Bohr A Real Bore Bohr - Bohr - electrons circles the nucleus & can jump levels Quantum Minimum energy req. for electron to move levels energy levels like steps.... not equally spaced. higher the step, more energy & farther away Energy Levels Sixth Fifth Forth Third Second First Nucleus A. All solid objects will change color when they are heated because they emit ________. Radiation - which is light The color that is produced by the emitted radiation depends on the _____ of the object. Temperature Example: Red glow from an electric stove Bohrs Model of the Atom Erwin Schrodinger (1887 1961) Quantum Mechanical Model mathematical model - predicts location and energy Electrons dont have definite energy level paths. 90% probability region denser the cloud, greater probability Schrdingers Famous Paradoxical Cat 1)cat in box, w/ a radioactive atom. 2)If atom decays, hammer hits flask w/ prussic acid 3)killing cat. Is the cat alive or dead? quantum mechanics, says: it wavers 50% dead 50% e- exists in all locations, 1 location & sometimes no location Electrons cant exist between levels & change Levels electrons by gaining/losing an exact quantity of energy (1 quantum) ELECTRONS IN SUB-ENERGY LEVELS WB P. 180 floor no. subLevel room bedS S P D F Electronic Configurations Aufbau Principle Aufbau Principle Electronic Configurations use your periodic chart page 1 use your periodic chart page 1 Electronic Configurations 1 st row 1 st row Electronic Configurations 1 st row 1 st row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 2 nd row 2 nd row Electronic Configurations 3 rd row 3 rd row Electronic Configurations 3 rd row 3 rd row Electronic Configurations 3 rd row 3 rd row Electronic Configurations 3 rd row 3 rd row Electronic Configurations 3 rd row 3 rd row Electronic Configurations 3 rd row 3 rd row Electronic Configurations 4 th row 4 th row Z= 2 Whats wrong with this?