LECTURE 1 OBJECTIVES1. 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 thenumber 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 charge5. Know what atomic mass and atomic weight mean and be able to calculate the number of protons, neutrons, and electrons foran 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)• 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 spontaneously9. Know that electrons occupy shells, and electrons in lower shells have less energy. Each shell has orbitals and each orbitalcan hold two electrons. This first shell has one orbital and can hold only two electrons, the next two shells have 4 orbitals andcan 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 max11. Be able to calculate how many unpaired electrons are present in the outer shell of an atom if you are given the atoms’ atomicnumber and its charge.LECTURE 2 OBJECTIVES1. Understand the concept of valence and know why atoms attempt to gain or loose electrons and participate in chemical bonds.• Valence: the number of electrons to gain or lose • 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)• they lose and gain electrons in order to have 8 paired electrons in the outer shell • make it more stable 3. Understand the differences between covalent (polar and nonpolar), ionic, and hydrogen bonds, and know which bonds arestrongest and which are weakest.• 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• 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 • hydrogen bonds• electrical attraction between compounds held together by polar covalent bonds(partial charges)• bond strenghts: (k cal/mole)• covalent: 70-100• ionic: 10-20• hydrogen: 4-5• Van der Walls 1-2• 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 thehydrogen having a partial positive charge. C-C and C-H covalent bonds are non polar.• O-H and N-H: polar covalent• O and N hold partial negative charge • H holds partial positive charge• C-C and N-H: polar covalent7. Be able to understand chemical formulas and structural formulas of molecules.• 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 • H-O-H9. Understand the concepts and be able to define: molecular weight, mole, molarity, solvent, solute• molecular weight: sum of the atomic weights of atoms in a molecule• ex: H2O molecular weights = 1 + 1 + 16 = 18 • mole: amount of a compound equal to its molecular weight in grams• H2O = 1 mole = 18 g• CO2 = 1 mole = 44 g• one mole of a compound contains 6 x 10^23 atoms• solvent: the dissolving medium• solute: the dissolved substance11. Be able to work with metric system units: meters, centimeters, millimeters, micrometers, nanometers; liters, milliliters,microliters; moles, millimoles, micromoles• kilo = 1000• milli = 10^-3• 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/L13. Be able to read and understand equations for chemical reactions• reactants - > products• 2H2 + O2 -> 2H2O15. Understand the concept of equilibrium in chemical reactions and be able to predict the direction of a reaction if you are givenits equilibrium constant (Keq• 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• A + B <---> C + DLECTURE 3 OBJECTIVES1. Understand how water hydrogen bonds to other water molecules, understand the structuraldifference 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• cohesion: ability of a substance to stick to itself• adhesion: ability of a substance to stick to another substance• water expands when it freezes:• H-bonds are stable• liquid water : H bonds break and reform 3. Be able to define heat and temperature.• heat: measure of total kinetic (movement) energy in a body• temperature: measure of the intensity of heat5. Be able to define specific heat, know that water has a high specific heat because of it's
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