Module 5

• Dalton's Atomic Theory - each element is made up of tiny particles called atoms
• Dalton's Atomic Theory - the atoms of a given element are identical
• Dalton's Atomic Theory - chemical reactions involve reorganization of the atoms, changes in the way they are bound together
• Dalton's Atomic Theory - the atoms themselves are not changed in a chemical reaction, they will remain the same even the reaction is done
• J.J Thomson's Atomic Theory - discovered the electron in his cathode ray tube
• J.J Thomson's Atomic Theory - plum pudding model of the atom
• Rutherford's Theory - used radon and some elements emits streams of positively charged particle through the gold foil experiment; atom is made up of mostly empty space and contained a positively charged nucleus
• 2Oth century - the development of mass spectrophotometers lead to the discovery of neutrons
• Elements - contains only 1 kind of atom
• Compounds - contains 2 or more kind of atoms
• Chemical bonds - attractive force that holds 2 atoms together in a more complex unit
• chemical bonds - result of interaction between electrons found in the combining atoms
• valence electron - an electron in the outermost electron shell of a representative element or noble-gas element
• lewis symbol - a chemical symbol of an element surrounded by dots which are representation of the valence electrons present in atoms of the element
• octet rule - states that it should have an eight electrons in a compound for it to be stable
• ionic bond - formed through the transfer of one or more electrons from one atom or group of atoms to another atom or group of atoms
• covalent bonds - formed through sharing of one or more pairs of electrons between 2 atoms
• covalent compound - interaction between 2 or more non-metals
• ionic compound - interaction between a metal and non-metal
• Valence Shell Electron Pair Repulsion Theory (VSEPR) - model used to predict the shapes of compunds
• Polar covalent bonds - having dipoles, a positive and a negative ends
• non-polar covalent bonds - do not have positive or negative ends
• Intermolecular forces of attraction (IMFA) - the attractive forces present between molecules
• London dispersion forces- - weakest type of IMFA; present in all molecules; caused by fluctuations in the electron distribution within atoms or molecules
• dipole-dipole forces - moderately strong type of IMFA; attractive forces between polar molecules; result of the electrical interactions among dipoles on neighboring molecules
• hydrogen bonding - strongest type of IMFA; special type of dipole-dipole forces; attraction between hydrogen + any electronegative molecule
• solubility - ability of a substance to dissolve in a given amount of solvent at a specified feature
• Strong IMFA - results to a packed close together; exists as condensed phase (solid or liquid)
• Weak IMFA - far from each other; exists as gas
• Melting point - temperature at which the substance changes from solid to liquid; stronger IMFA, higher MP. This means greater amount of energy is needed to break the attractive forces between molecules
• Boiling point - temperature at which the substance changes from liquid to gas
• surface tension - tendency of a fluid to acquire the least possible surface area
• Biomolecules - large organic compounds that are important to life's processes, such as respiration and metabolism
• Proteins - macromolecules comprised of one or more long chains of amino acid residues joined together by peptide bonds
• amino acids is the basic unit of proteins
• transport proteins - carry small particles throughout the body
• Carbohydrates - molecules that are composed of carbon, hydrogen, and oxygen
• Monosaccharides - simple sugars (glucose)
• Disaccharides - two monosaccharides bonded together (maltose, sucrose, lactose)
• Polysaccharides - many monosaccharides bonded together (starch, glycogen, cellulose)