2DRY ERASE ATOM ATTITUDE Everyone gets a dry erase board, dry erase pen, and tissue for erasing.The teacher will ask you a question about atomic structure, you will write your answer and hold up your board.
3Are you wondering why we are learning chemistry in biology class? All of our cells are made of chemical compounds.All the activities of our bodies work on chemical reactions.All of our body’s reactions use water.Such as neurotransmitters affecting neurons
4MATTERAnything that occupies space (VOLUME) and has MASSIs air matter?Yes
5Match as energy (capacity to do work) or matter (occupies space and has mass) WaterElectricityAirHeliumSunlightIronCarbonMatterEnergy
8YOU NEED TO KNOWThe Names (spelled correctly) and the Symbols (written correctly) on p. 18 (Table 2.1)“Elements in the Human Body”25 elements (includes trace elements)QUIZ on FRIDAY Sept. 27
9ELEMENTSSubstance that cannot be broken down to other substances by ordinary chemical means (heating, adding an acid…)YouTube - ?Tom Lehrer'sThe Elements" animated??****ASAP SCIENCE Periodic TableIn OrderOR YouTube - ?The Elements Animation??
10Where can you find an element? The Periodic Table of the Elements – see Appendix 2 and get your personal copy
11ELEMENTS AND SYMBOLS: Ca, H, Li, O, C, Mg What rules apply to writing the symbols (abbreviations of the elements)?First letter capital, second letter is lower caseWhat are the four most common elements in the human body? (see chart)CHONWhat are trace elements?Less than 0.01% of human body weight
12Which are elements? Cu C CO N NO WHY? Cu C N only one kind of matter Gold - Au
13COMPOUNDSSubstance of two or more different atoms chemically combined in a fixed ratioEXAMPLES: CO2H2SO4H2OCOHow is a compound written differently than an element?More than one kind of element (more than one capital letter).NOTE: H2 is not a compound – its an element(Only one kind of element)Subscripts (tell how many atoms there are)
14Formula Formula is the abbreviation for a compound. CO2 H2SO4 H2O Carbon dioxide sulfuric acid waterWhat rules seem to apply to writing a formula?Capital letters for elementsSubscript number behind and just below the line of what element it represents
15Which are compounds? Na N H2 NO2 H2O Why? NO2 H2O 2 or more different elements chemically joined (2+ diff. capital letters)
16Which are symbols? Abbreviations for elements C CO2 Mn CO Ni Why?C Mn NiOnly one capital letter
17What’s the difference?Co CO coSymbol formula nothing
18Which are formulas? Abbreviation for a compound H2SO Cl H Al Why?H2SO H20 abbreviations for compounds (2 or more different kinds of elements)
19Can you figure out the difference between a mixture and a compound? A mixture is two or more elements (or compounds) NOT chemically joined.A compound is two or more atoms chemically joined.Do Worksheet: Elements, Compounds, Mixtures
20DO WORKSHEET: Elements, Compounds, Mixtures (back of Atomic Mass and Atomic Number Worksheet)Work in groups of three, then we’ll compare answers.
212.2 What are trace elements? Needed in the body in only small amountsLike mg (milligrams)WHY IMPORTANT IF WE DON’T NEED SO MUCH?Minerals act as catalysts (speed up reactions) for many biological reactions
22Trace Elements Needed by some organisms but only in very small amounts Like iodine, we need only 0.15 mg per dayA deficiency will cause a goiter
23Trace Elements Fluorine – in drinking water, toothpaste (help dental decay)But too much can cause fluorosis (white chalky build-up)
24Trace Elements Iron Rich Foods Most important use is to carry oxygen in the blood
50Which is the most common isotope of Li? (check the periodic table)
51Why is the Mass Number a Decimal? Finding the Average Atomic Mass (2:55)Watch this and find out how…
52How do you write chemical notation for isotopes?
532.4 Radioactive IsotopesAn isotope that decays spontaneously to emit (give off) particles or energy until it is stableHere a radioisotope is used to examine a thyroid glandRadioactive Tracers in Medicine (3:57)
55Uses of RadioisotopesC-14 dating (can date living things up to 6,000 years old) Carbon Dating (2:00 mins)Technetium 99 Radioisotope (2:58)Nuclear Medicine: What to expect (2:46 mins)Bozeman Biology Radioactive Dating (9 mins)Carbon-14 Dating (2 mins)PET SCAN: detect tumors, weak spots in arteriesHighlight parts of the body for diagnosisThyroid tumor
56Uses of Radioisotopes Iodine-131 PIB molecule to treat thyroid cancer detect AlzheimersPET scan
57Negative Effects of Nuclear Radiation Chernobyl Nuclear Plant Accident
58Negative Effects of Radon Radon, a radioactive gas, causes lung cancerFound in regions containing uranium
63O-2 has gained two electrons Na has lost an e- so it is Na+1
64Cation Positive ion Na+ Mg+2 Lost electrons Negative ion Cl- O-2 AnionPositive ionNa+Mg+2Lost electronsNegative ionCl-O-2gained electrons
65+1 If one electron is… Lost what charge will the ion have? 11p+ 11 e-
66Which are ions? Cl O-2 Na+1 N2 Why? O-2 Na+1 Charged atoms (lost or gained electrons)show charges as superscripts
67Valence Electrons Outer shell electrons Determines the bonding capacity of an atom
68How do electrons arrange themselves in an atom… In the outer electron shells (energy levels)?They are full with 2, 8, 8Fill inner shell first,then go to next shell out(Outermost shell has the greatest energy)Can you see any pattern howthe e- arrange themselves?
69Get kinda complicated beyond 2,8,8…so that’s all we’ll do for now!
71Which electrons determine… The chemical properties of the atom?Outermost shell
72If one electron is gained… What charge will the ion have?-1
73-2 +2 If 2 electrons are lost… What charge will the ion have? If two electrons are gained… What charge will the ion have?-2
74Filled outer e- shellsHow many e- fill the first shell (nearest the nucleus)?How many e- fill the next two shells?nucleus
75Gain 1 e- or lose 7 e-?If gains 1 e-, then it becomes -1
76Gain 7 e- or lose 1 e-?If loses 1 e-, the it becomes +1.
77Gain or Lose ?If it could as easily lose or gain e-, then it will probably share them. It will form a covalent bond.Tutorial 2.1 Chemical Bond Formation
78Fill in the chart of e- Element Number of e- First shell Second Third Shell Shellcarbon6lithium3Sodium11Oxygen16
79Fill in the chart of e- Element Number of e- First shell Second Third Shell Shellcarbon624lithium31Sodium11Oxygen8
80How are ion charges determined? Cation = positive (+) ionAnion = negative (-) ion
81How are ion charges determined? If lose 1 e- = +1 chargeIf gain 1 e- = -1 chargeIf lose 2 e- = +2 chargeIf gain 2 e- = -2 charge
82Periodic Table Hint:You can tell how many electrons are in an atom’s outermost shell by just looking at its position on the periodic table!!!!!
83Note any pattern of valence electrons (outer shell) as they appear in the periodic table?
84e- in outer shells +1 +2 Ion formed e- in outer shell share -3 -2 -1 0 +1 +2Ion formedsharee- in outer shells8e- in outer shellHFull outer e- shells
85How many electrons in each shell? (atomic number is given) Carbon oxygen fluorine sodium2, , , ,8,1
86How many valence electrons How many valence electrons? Will these atoms lose or gain e- and how many?
87How many valence electrons How many valence electrons? Will these atoms lose or gain e- and how many?Lose lose O lose share gain lose 1H He Li C N Na+
88Now let’s do the Drawing Atoms Worksheet (and next 4 slides) How the electrons fill their shells (link)1st shell – 1 pair2nd shell – e- space far apart, singles, then pair3rd shell – e- space far apart, singles, then pair
97See the trend of how electrons fill the valence shells Lewis dot structuresOctet Rule – electrons fill a shell until it’s full with 8 electronsAtoms are most stable with a filled outer electron shell
98What do we call the forces that… Hold atoms together in a molecule?Chemical bonds…not to be confused with James Bond
99To have filled outer electron shells! Why do atoms bond?To have filled outer electron shells!Atom HeavenATOM
100What is a chemical bond?Attraction between two or more atoms YouTube - ?Ionic and covalent bonding animation??
123Electronegativity Tendency of an atom to attract electrons towards itself and thusthe tendency to form negative ions.
124Electronegativity NONPOLAR – equal sharing of electrons The more electronegative atom pulls shared electrons toward its nucleus.NONPOLAR – equal sharing of electronsPOLAR – unequal sharingof electrons
125H = 2.1 O=3.5 C=2.5 Electronegativities H-H = 0.0 bond pure covalent O-H bond = 1.4 polar( )covalentNaCl = 2.1 ionic
126MoleculeA group of two or more atoms held together by covalent bonds
127What’s the difference between Intramolecular and Intermolecular Forces?
128What’s the difference?Intermolecular attractions are between one molecule and a neighboring molecule(Van der Waals, hydrogen bonds)USUALLY WEAKERIntramolecular attractions are the forces which hold an individual molecule together (for example, the covalent bonds or ionic bonds).USUALLY STRONG
129WHAT IS THE STRENGTH COMPARISON? STRONGEST BONDWEAKEST BONDCovalentIonicHydrogenVan der Waals(dipole-dipoleLondon forces)intramolecular
130INTERMOLECULAR FORCES A. H-bonds (H to F, O, or N)B. van der Waals- temporary “dispersion” London (nonpolar) and dipole-dipole forces (polar)C. Disulfide bridges (-S-S-)Intermolecular Forces Youtube (9:11-if ya got time)
131Intermolecular Forces video and worksheet What three types of intermolecular forces are there?What does dipole mean? Why do those molecules attract each other?London forces are in molecules that are not dipoles. What do they do to their e- to cause an attraction?What three possible atoms can make a hydrogen bond with hydrogen?List the forces in order of strength.
132Hydrogen Bonds: Intermolecular between H and F, O, or N
133Where Might you find Hydrogen Bonds? In Water – between O- and H+In DNA – between bases
134Intramolecular: Van der Waals Van der Waals on Gecko Feet (8:22)Is the sum of the attractive forces between molecules (but not H-bonds or covalent bonds)
135van der Waals Temporary dispersion of electrons make temporary charges Van der Waals Dispersion ForcesTemporary dispersion of electrons make temporary charges
136Where might you find van der Waals? crystal structures (e. g. the shapes of snowflakes),DNA shape
137Intramolecular: (Van der Waal type) Dipole-dipole exists between neutral polar molecules only when they are close togetherDipole Forces Bozeman youtube (7:32)Temporary shift of the electrons to make a partial + and a partial - end
138Weakest van der Waals: London Dispersion Forces Temporary polarity between nonpolar atoms or moleculesAll molecules have them at some timeBozeman London Dispersion Forces (5:02)
139London Dispersion Force London Dispersion Force Animation
140Disulfide Bonds: Protein Tertiary Structure Disulfide Bond in Tertiary Protein
141Disulfide Bondsformed between the side chains of cysteine in a protein SH) to form a disulfide bond (S-S)(Will learn about this in Chapter 3)
142THEME OF EMERGENT PROPERTIES New properties that arise with each step upward in the hierarchy or life, owing to the arrangement and interactions of parts as complexity increases.WHOLE IS GREATER THAN THE PARTS
143How is the emergent property idea apply to a compound and atoms? HINT:
1442.9 Chemical ReactionsThe making and breaking of chemical bonds, leading to changes in the composition of matter.
145Chemical Reactions Reactants on the left of the arrow Products on the right of the arrowIDENTIFY:2Mg(s) + O2(g) → 2MgO(s)MgO(s) + H2O(l) → Mg(OH)2(s)N2(g) + 3H2(g) → 2NH3(g)
146Same number of each element on left side as on the right side CH4 (g) + 2O2 (g) CO2 (g) + 2H2O (g)ReactantsProductsC = 1H = 4O = 4
147Signs of a Chemical Reaction Precipitate formsColor ChangeGas FormsTemperature change
148Chemical Reaction Videos Na and Cl Chemical Rx (52 secs.)Genie in a Bottle Reaction - Steve Spangler (3:36)Weirdest Chem. Rx in the World (2:52) Mercury(II) thiocyanate Hg(SCN)2The Naked Scientists Videos (MP3)
149Chemical Reaction Example An iron bar rusts. The iron reacts with oxygen in the air to make rust. 4 Fe + 3 O2 2 Fe2O3