Composition of Matter and Its States Elements the most basic chemical component Compounds when th elements combine Mixtures compounds mixed Chemists study the structure of matter and how it undergoes change Matter is characterized by physical and
Fundamentals of Quantum mechanics Mathematical physics provides new insights which lead the way to understanding chemical bonding 20th century pioneers Subatomic particles display wave like properties that can be modeled through the use of wave equat
A simple Model of atomic structure Unresolved issues Rutherford model offers no clue on how the electrons are arranged around the nucleus Atoms would collapse if they were just in `plum pudding model' Bohr model of the atom `planetary model of atom'
Early Atomic Models Atoms are composed of charged particles protons and electons Spontaneous radioactive decay creates alpha and beta particles as well as gamma rays Xrays can penetrate seemingly continuous matter Rutherford experiment Alpha paricles
Oil Drops and X-Rays Millikan oil drop experiment Negatively charged particles floated down As voltage increased attraction to positive plate increased and particle was suspended in air Able to see the mass of electron Mass of electron 9.1 x 10^-28
Inside the Atom
Silicon’s surface atoms
Si critical to semiconductor industry
Imaging of individual atoms!
Volta’s early contribution
Made the first battery that brought electricity under control.
Electrolysis of molten salts
Humphrey Davy discovered that
Mendeleev's Breakthrough Born in 1834 the last of 14 children Began his greatest work by age 30 First introduced to chemistry in father's glass factory Basis of periodicity Arrange elements in increasing order of atomic elements Classify them into gr
Understanding Periodicity Alphabetical List of elements makes no sense Atomic Mass weighs in Dalton couldn't measure absolute mass, but it was possible the relative the relative masses of the elements by decomposition and definite proportions Berzeli
Definite Proportions Systematic studies of compounds lead to the earliest atomic theory John Louis Proust Decomposition of CuCO3 always yields the same elemental products in the same definite proportions source is irrelevant Law of definite proportio
Chemical Revolutionaries Sir Robert Boyle `The Sceptical Chymist' Substances couldn't be decomposed into elements Compounds result from combination of elements Antoine Lavoisier He and his wife were true chemical revolutionaries She translated into F
Chemistry through the Renaissance Looking from the 21st century Individual Au atoms imaged using atomic force microscope Aristotle's view point Reasoned that matter was continuous based on human perception No experimental approach to test the theory
Common Chemical Measurements SI vs. English Inch = 2.54 cm Liter 1 L = 1000cm3 Density = Mass/volume Energy is conserved changes type: chemical kinetic electrical heat potential radiant Einstein found a loophole for conversion of mass to energy E=mc
Physical Measurements SI units Based on the decimal to make scaling easy http:/physics.nist.gov/ccu/Units 1 kilograms = 1000 grams 1 lb 16 ounces Common SI units Lenth meter m Mass kilogram kg Time Temp Kelvin K Amount mole mol Electric current Lumi
Substances and Mixtures Elements cannot change into other elements Carbon Diamonds and Graphite Both extended structures with no chemical formula other than C Diamonds very strong bonds Graphite weaker bonds "Buckyballs" A definite chemical formul
Revisiting Chemical Periodicity Each suborbital hold two electrons N1 2 N2 8 N3 16 N4 32 S, p, d and f suborbitals How suborbitals fill in atoms 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 5d, Transition metals fill d Sucessive rows of the periodic table