LECTURE 1 OBJECTIVES 1 Know the definitions of elements atoms compounds and molecules elements substance that cannot be broken down into a simpler substance in a chemical reaction its in its simplest form atom the smallest unit of an element retaining its properties compounds combos of elements in different proportions 3 Understand that atoms of each element have a characteristic number of protons and that the number of protons equals the number of electrons in an uncharged atom atomic particles are composed of subatomic particles neutrons no charge neutral protons positive charge electrons negative charge protons electrons if there is no charge 5 Know what atomic mass and atomic weight mean and be able to calculate the number of protons neutrons and electrons for an atom if you are given its atomic number atomic mass and its charge atomic mass sum of protons and neutrons in the nucleus atomic number the number of protons in its nucleus for uncharged atoms this is the same as the number of electrons cid 127 mass protons neutrons number protons or electrons 7 Be able to explain what an isotope is two atoms of an element that differ in number of neutrons same element same chemical properties but different physical properties radioactive isotopes are unstable their nuclei decay spontaneously 9 Know that electrons occupy shells and electrons in lower shells have less energy Each shell has orbitals and each orbital can hold two electrons This first shell has one orbital and can hold only two electrons the next two shells have 4 orbitals and can hold a maximum of 8 electrons electron shell the location relative to the nucleus of an electrons state of potential energy energy shells third shell highest energy level second shell higher energy level first shell lowest energy level outer shell valence shell atoms try to lose or gain electrons until the outer shell is filled 8 e each shell has orbitals orbtials can hold 2 electrons shell 1 1 orbital 2 electrons shells 2 3 4 orbitals 8 electrons max 11 Be able to calculate how many unpaired electrons are present in the outer shell of an atom if you are given the atoms atomic number and its charge LECTURE 2 OBJECTIVES 1 Understand the concept of valence and know why atoms attempt to gain or loose electrons and participate in chemical bonds cid 127 Valence the number of electrons to gain or lose cid 127 monovalent 1 electron Na K Cl divalent 2 electrons Ca Mg O trivalent 3 electrons Fe Al tetravalent 4 electrons C pentavalent 5 electrons p cid 127 make it more stable strongest and which are weakest they lose and gain electrons in order to have 8 paired electrons in the outer shell 3 Understand the differences between covalent polar and nonpolar ionic and hydrogen bonds and know which bonds are covalent sharing electrons with another atom stabilizes ex two H bonds share their electrons to form a molecule of hydrogen gas non polar covalent electrons are shared equally cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 identical atoms polar covalent one atom has one electron more frequently atom that pulls the electron hardest is more electronegative ionic when an electron is stolen by one atom from another they are not shared it is taken each atom has one full charge and the atoms are held together by electrical attraction electrical attraction between compounds held together by polar covalent bonds partial charges hydrogen bonds bond strenghts k cal mole covalent 70 100 ionic 10 20 hydrogen 4 5 cid 127 Van der Walls 1 2 cid 127 Van der Walls interactions weak attraction of uncharged atoms 5 Know that O H and N H covalent bonds are polar with the oxygen and nitrogen holding a partial negative charge and the hydrogen having a partial positive charge C C and C H covalent bonds are non polar cid 127 O H and N H polar covalent cid 127 O and N hold partial negative charge cid 127 H holds partial positive charge cid 127 C C and N H polar covalent 7 Be able to understand chemical formulas and structural formulas of molecules cid 127 molecular formulas identifies the elements and the number of given atoms in a molecule ex H2O structural formulas show the number and arrangement of covalent bonds in a molecule cid 127 H O H 9 Understand the concepts and be able to define molecular weight mole molarity solvent solute cid 127 molecular weight sum of the atomic weights of atoms in a molecule ex H2O molecular weights 1 1 16 18 cid 127 mole amount of a compound equal to its molecular weight in grams cid 127 H2O 1 mole 18 g cid 127 CO2 1 mole 44 g solvent the dissolving medium solute the dissolved substance one mole of a compound contains 6 x 10 23 atoms 11 Be able to work with metric system units meters centimeters millimeters micrometers nanometers liters milliliters microliters moles millimoles micromoles kilo 1000 cid 127 milli 10 3 cid 127 micro 10 6 1 L 1000 mL 1mL 1000 L 1 mole 1000 mmoles 1 m 1 mole L 1mM 10 3 mole L 1mM 1 6 L 10 3 mM L reactants products 2H2 O2 2H2O 13 Be able to read and understand equations for chemical reactions 15 Understand the concept of equilibrium in chemical reactions and be able to predict the direction of a reaction if you are given its equilibrium constant Keq cid 127 most chemical reactions do not go to completion and are reversible at equilibrium there is no net change in the concentrations of the substance reactants and products equilibrium constant Keq ratio of concentrations of products and substrates at equilibrium cid 127 A B C D cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 cid 127 LECTURE 3 OBJECTIVES 1 Understand how water hydrogen bonds to other water molecules understand the structural difference between liquid water and be able to explain why ice expands upon freezing waters properties come from its polar covalent bond and its ability to form H bonds cid 127 cohesion ability of a substance to stick to itself cid 127 adhesion ability of a substance to stick to another substance cid 127 water expands when it freezes cid 127 H bonds are stable liquid water H bonds break and reform 3 Be able to define heat and
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