The Chemistry of LifeThe Chemistry of LifePresented By:Mrs. Nelson
““Matter and Elements”Matter and Elements” Everything on earth is made of matter Matter - has mass and takes up space(volume). Matter is made up of atoms. Atom - smallest unit of matter. Element – made of only one type of atom.
Periodic TablePeriodic TableElement Symbols to LearnElement Symbols to Learn Hydrogen Carbon Nitrogen Oxygen Sodium Magnesium Silicon Phosphorus Uranium Sulfur Chlorine Potassium Calcium Iron Zinc Iodine Mercury Lead
““Structure of the Atom”Structure of the Atom” Nucleus: corecontains protonsand neutrons Protons (+) Neutrons (0) Electrons (-) orbitthe nucleus Atoms areelectrically neutral.
““Element Key”Element Key”Atomic #SymbolAtomic Mass
Mass of an AtomMass of an Atom The mass of an atom is due to the mass of protons,neutrons, electrons. Protons and neutrons are HUGE vs. electrons. Protons and neutrons have essentially the same mass(1 amu). The more protons and neutrons, the heavier theatom. Electrons have essentially no mass (0.00001 amu). Most of the mass of atom located in nucleus.
Atomic Mass vs. Mass NumberAtomic mass- average mass of all theisotopes of an element (listed on theperiodic table)Mass Number- the amount of all theparticles with “significant” mass in an atom(technically not given on the periodic table)-protons + neutrons
““Element Key”Element Key”Atomic #SymbolAtomic Mass(determines mass number)
IsotopesIsotopesAll atoms of same element have same # ofprotons and electrons.Ex.) Carbon has 6 protons and 6 electrons.Not all atoms have same # of neutrons.Carbon has 3 isotopes: Carbon-12, Carbon-13, Carbon-14
Isotopes (cont.)Isotopes (cont.)Carbon has an atomic number of 6.This tells us?Carbon atoms all have 6 protons.Carbon has 3 isotopes: C-12, C-13, C-14.
IsotopesIsotopesHow many neutrons does each have?To determine the number of neutrons –must subtract number protons from massnumberCarbon-12 (6 p, 6 n, 6 e)Carbon-13 (6p, 7 n, 6 e)Carbon-14 (6p, 8n, 6 e)* The atomic mass of an atom is calculated byaveraging the masses of all the isotopes ofan element.
“Happy vs. Sad Atoms” Atoms want tohave full outerlevel of electrons. 2,8,8 Valenceelectrons
“Atomic Bonding”In order for atoms to be “happy,”they must gain, lose, or shareelectrons.Results in “bonding.”When atoms bond, they formcompounds.
Chemical FormulasChemical FormulasShows …1. The types of atoms in the compound.2. The number of atoms in the molecule.3. The total number of molecules.CO2Subscript2Coefficient
Chemical BondsChemical BondsThe atoms in a compound are held togetherby chemical bonds.There are two general types of chemicalbonds.1. Ionic bonds2. Covalent bonds
““Ionic Bonding”Ionic Bonding”Ex.) Sodium ChlorideResults in atoms losing orgaining electrons.“Ions” are formed.“Ions” atoms with charges.Charge results from an unequalnumber of protons and electrons.
““Covalent Bonding”Covalent Bonding”Sometimes atoms don’t like to giveor take electrons.Atoms may “share” electrons.
“Polarity” Sometimes sharing is“unequal.” In water, the oxygenatom “pulls” harderon electrons. Gives oxygen anegative charge andhydrogen positivecharge.
The Chemistry of WaterThe Chemistry of WaterWater is the single mostabundant compound found inliving things.Water is an essential componentto your cells.The inside of every body cellconsists of over 90% water.
The Water MoleculeThe Water MoleculeWater molecules contain“covalent” bonds.The water molecule is“polar.”Negative pole is near theoxygen end.Positive pole is near thehydrogen end.
Hydrogen BondsHydrogen BondsBecause of their partial+ and – charges, watermolecules attract eachother.Remember… Oppositesattract!!!
CohesionCohesionThe hydrogen bonds thatform between watermolecules are what allowsspiders to walk on water.Water is cohesive.Cohesion is the attractionbetween molecules of THESAME substance.Water sticks to itself.
AdhesionAdhesionAdhesion is the attraction between moleculesof DIFFERENT substances.Water sticks to other stuff!
SolutionsSolutionsWater is not always pure.It is often found mixed with other substances.Solutions occur when a substance is dissolved inwater. The substance is evenly distributedthroughout the water.In every solution, there is a solute and solvent.The solvent does the dissolvingThe solute gets dissolved.Ex.) saltwater
SuspensionsSuspensionsA suspension occurs when materials don’tdissolve in a substance.Ex.) Italian salad dressing.Ex.) Blood – actually is a solution and asuspension.