BSC2010 EXAM 1 DENNISChapter 1-6 in BOOKLecture NOTES 1-71/10/12- Hydrocarbons - stronger bonds (gasoline)- Matter consists of pure elements and combinations of elements called compoundso organisms are composed of mattero matter = anything takes space and has mass-Elements and compounds-matter is made up of elements-element is a substance that cannot be further broken down by chemical reactions-compound = substance consisting of 2 or more elements in a fixed ratioPeriodic Table-Rows top to bottom are layers of electrons-First Shell, Second shell, Third Shell-Outermost shell can contain 8 electrons-Outermost shell goes from left to right starting with 1 then 2, 3, 4 all the way to 8Essential elements in life (Figure 2-1)- About 25 elements are essential-C, H, N, O Make up 96% of living matter- Most of remaining 4% is Calcium, Phosphorus, potassium, sulfur-Trace Elements are required in minute quantitiesElements properties depend on structure of atoms-Sodium (explosive metal) + Chlorine(dangerous Chemical) = Sodium Chloride- Emergent property - New Property formed by compounds-Each element consists of unique atoms-An atom is smallest unit of matter that retains the property of an element-Atoms are composed of subatomic particlesON TEST************************Particle Charge Mass LocationNeutron Neutral (0) 1 Dalton Atomic NucleusProton Positive 1 Dalton Atomic NucleusElectron Negative No Mass (0) Electron Cloud*************************Isotopes- All Atoms of an element are defined by the number of protons -Isotopes are two atoms that differ in the number of neutrons-Unstable, giving off energy-Energy level of electrons-Energy is the capacity to cause change-Potential energy is energy due to location or structure-Electrons (e-) of an atom differ in their energy-Lowest Shell is located closest to Atomic Nucleus-Lowest Shell has lowest energy-Highest Shell has Highest Energy(Glow in the dark - Light gives energy to bump up electrons and as they fall back down, a faint light is given off)Electron distribution and chemical properties-Chemical behavior of atom is determined by the distribution of electrons in electron shells**-The Period Table shows the electron distribution for each elementON TEST *************************See a periodic Table (Day two slides)- asking to provide number of electrons- Atomic number or mass - Given the name of element*************************-Once a lower shell is filled it is no longer needed to understand electron-Valence Electrons are outermost shell-Outermost Shell is Valence Shell-The Chemical Behavior of Atom is determined mostly by valence electrons-Elements with full valence shells are full at maximum capacity (8) = Chemically inert(Do not react)-Electronegativity is the propensity of an element or the atom of an element to pull electrons-From Bottom left(Giving) to Top Right(Taking) - Electronegativity Increases**********************-WHAT IS THE MOST ELECTRONEGATIVE ATOM THAT MAKES UP 96% OF LIVING MATTER? - OXYGEN**********************Not Giving or taking = CARBON -Simplest/smallest perfect sharer of electrons-Carbon is backbone of lifeHydrogen-Has one electron-Can hold up to two -Would add one-Equally Shared-would bring together two hydrogen to make stable compoundH: H- ^ Stable Covalent BondCarbon-Has four-Would need four-total of 8-covalent bond with perfect sharingOxygen-More electronegative-Hydrogen are shared -Lowercase delta on drawing used to show partial charge-bonds are easier to break-Polar covalent bond - unequal sharing of electrons-Non polar covalent bond - are equal sharing of bondsChlorineSo electronegative that it strips hydrogen of its one electron7 protons and 7 neutronsCovalent bonds-Polar and non polarBecause you know the behavior thats represented, the shells, valence, electrons, and number to fill in outer shel in addition to electronegativityyou can pair up any atoms of any elementsyou can understand if bonds are shared perfectly or non perfectly-shared unequally you define them as partially negative or positive-An ionic bond- Pair up any of the atoms of any elements- The pairing is with an atom that is so electronegative it strips away the electron of another elementHydrogen Bonds-found in anythingWater-Hydrogen bonds found in water are ultimately responsible for life on earth-Ice forming in lattice is less dense so it floats, if it sank it would build and build-The ends and sides of water make it so that the water arranges itself in solid and liquid form in predictable mattersHydrogen bonds are weak interactionsMany weak interactions = create an incredibly strong interaction1/15/13Hydrogen Bonding Water-partial negative and partial positive charge-oxygen is a taker of electrons = more negativeWater - appears to be unique to earth-Covers 3/4 of the earth’s surface-Constitutes 60-70% of the weight of all life-regenerates and is redistributed through the water cycle-only molecule that exists naturally on earth in all three states (Gas, solid, liquid)-absolutely essential to LIFEConcepts-Hydrogen Bonding-Emergent Properties-Acid/Base chemistry**********************MUST BE ABLE TO DRAW WATER AND DIPULL MOMENT?H H\ / O**********************Solid Form - Ice-Organized Hydrogen Bonds -stable-Crystal lattice Ice-Hexagonal Lattice-More spacious than the liquid formLiquid Form-Fragile Disorganized Hydrogen bonds-Last only few trillionths of a second-constantly broken and reformedGas Form -single molecules-liberated by edition of energyEmergent Properties of WATER-make H2O ideal for life on earth-Adhesion, cohesion, surface tension-ability to moderate temperature-evaporative cooling-expansion upon freeing-universal solventAdhesion, Cohesion, Surface TensionCohesion- Phenomenon of Hydrogen Bonds holding water togetherSurface Tension- Measure of how hard to break surface of liquidAdhesion- the phenomenon of Hydrogen Bonds of water holding that water to something elseTrees- As one molecule is lost due to the cohesion of water another is brought upAbility to Moderate Temperature-Water absorbs heat from warmer air and releases stored heat to cooler air-can absorb a huge amount of heat/energy with a slight change in its own temperature-EX: Shining two heat lamps - one on water and one on steel - water would be cooler-Water has a high specific heat-Specific Heat = the amount of heat, that must be absorbed or lost for 1 gram of that substance to change its temperature by 1 degree celcius-1 ml of water weighs 1 gram-1
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