Presentation on theme: "Honors Biology Chapter 2 Chemistry. DRY ERASE ATOM ATTITUDE Everyone gets a dry erase board, dry erase pen, and tissue for erasing. The teacher will ask."— Presentation transcript:
Honors Biology Chapter 2 Chemistry
DRY 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.
Are 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 bodys reactions use water. Such as neurotransmitters affecting neurons
MATTER Anything that occupies space (VOLUME) and has MASS Is air matter? Yes
Match as energy (capacity to do work) or matter (occupies space and has mass) Water Electricity Air Helium Sunlight Iron Carbon Matter Energy Matter Energy Matter
2.1 ELEMENTS, ATOMS, COMPOUNDS (are matter)
YOU NEED TO KNOW The 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
ELEMENTS Substance that cannot be broken down to other substances by ordinary chemical means (heating, adding an acid…) YouTube - ?Tom Lehrer's The Elements" animated?? ****ASAP SCIENCE Periodic Table In Order OR YouTube - ?The Elements Animation??YouTube - ?The Elements Animation??
Where can you find an element? The Periodic Table of the Elements – see Appendix 2 and get your personal copy
ELEMENTS 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 case What are the four most common elements in the human body? (see chart) CHON What are trace elements? Less than 0.01% of human body weight
Which are elements? Cu C CO N NO WHY? Cu C N only one kind of matter Gold - Au
COMPOUNDS Substance of two or more different atoms chemically combined in a fixed ratio EXAMPLES: CO 2 H 2 SO 4 H 2 O CO How is a compound written differently than an element? More than one kind of element (more than one capital letter). NOTE: H 2 is not a compound – its an element (Only one kind of element) Subscripts (tell how many atoms there are)
Formula Formula is the abbreviation for a compound. CO 2 H 2 SO 4 H 2 O Carbon dioxide sulfuric acid water What rules seem to apply to writing a formula? Capital letters for elements Subscript number behind and just below the line of what element it represents
Which are compounds? Na N H 2 NO 2 H 2 O Why? NO 2 H 2 O 2 or more different elements chemically joined (2+ diff. capital letters)
Which are symbols? Abbreviations for elements C CO 2 Mn CO Ni Why? C Mn Ni Only one capital letter
Whats the difference? Co CO co Symbol formula nothing
Which are formulas? Abbreviation for a compound H 2 SO 4 Cl 2 H 2 0 Al Why? H 2 SO 4 H 2 0 abbreviations for compounds (2 or more different kinds of elements)
Can 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
DO WORKSHEET: Elements, Compounds, Mixtures (back of Atomic Mass and Atomic Number Worksheet) Work in groups of three, then well compare answers.
2.2 What are trace elements? Needed in the body in only small amounts Like mg (milligrams) WHY IMPORTANT IF WE DONT NEED SO MUCH? Minerals act as catalysts (speed up reactions) for many biological reactions
Trace Elements Needed by some organisms but only in very small amounts Like iodine, we need only 0.15 mg per day A deficiency will cause a goiter
Trace Elements Fluorine – in drinking water, toothpaste (help dental decay) But too much can cause fluorosis (white chalky build- up)
Trace Elements Iron Rich Foods Most important use is to carry oxygen in the blood
2.3 Atoms and Molecules
Atoms are made of protons, neutrons, electrons Do you know what these particles are?
Answers: Do you know what these particles are? Protons Neutrons Electrons
Atom Smallest unit of matter that retains the properties of the element Li Na
Which shows one atom? C N N 2 H 2 0 Why? C and N only one in number Which are elements? C N N 2
Molecule Two or more atoms held together by chemical bonds
Which are molecules? Co CO CO 2 O 2 Why? CO CO 2 O 2 two or more atoms (alike or not alike, it doesnt matter) bonded together
Where is each subatomic particle located? Proton in the Neutron nucleus Electron-outside the nucleus Golden Retrievers Show Atomic Structure Youtube (2:11)Golden Retrievers Show Atomic Structure Youtube
What is the charge of each subatomic particle? Proton Neutron Electron + O _ positive none negative
What is the relative size? Proton neutron electron 1 amu 1 amu ~1/1836 amu AMU = atomic mass unit = 1/12 CARBON ATOM (standard)
Neutral Atoms (no charge) (as seen on the periodic table) 39 Mass Number p + n K Symbol 19 Atomic Number p (electrons = number of protons) Neutral if negative charges = positive )
How can you tell the mass number and atomic number?
When looking on the periodic table… Atomic Number In order Identify element by its number of protons Mass Number A decimal (average of masses of all isotopes of that element)
Why is the mass number a decimal? Average of the Isotopes of Carbon What is the mass number decimal? What would you round it to? 12
What is the atomic number of? Silicon fluorine sodium WHY? Number in succession (not a decimal) Number of protons
What is the mass number of…? Carbon nitrogen hydrogen WHY? Decimal number on periodic table Not other number in succession Number of p + n
How do you find the number of…? Protons electrons neutrons Atomic atomic mass number number number minus atomic no. (if neutral)
How many? Protons electrons neutrons Carbon Chlorine
What is the atomic number? Mass Number? Number of p? Number of e-? Number of n?
Do Atomic Mass and Atomic Number WORKSHEET Collaborate with your partner next to you, then well see whats right.
ISOTOPES INTRO Isotopes (Virtual School) (2:51)Isotopes (Virtual School) Watch the video and list what facts you learned about isotopes. No, not about the Albuquerque Isotopes
Isotope Atoms that differ in number of neutrons Also differ in mass number ( since it is p + n ) But all have the same number of protons
Isotope Examples What are isotopes? (7:56)What are isotopes?
Which is the most common isotope of Li? (check the periodic table)
Why is the Mass Number a Decimal? Finding the Average Atomic Mass (2:55)Finding the Average Atomic Mass Watch this and find out how…
How do you write chemical notation for isotopes?
2.4 Radioactive Isotopes An isotope that decays spontaneously to emit (give off) particles or energy until it is stable Here a radioisotope is used to examine a thyroid gland Radioactive Tracers in Medicine (3:57)Radioactive Tracers in Medicine
Radioactive Decay Examples
Uses of Radioisotopes C-14 dating (can date living things up to 6,000 years old) Carbon Dating (2:00 mins) Carbon Dating Technetium 99 Radioisotope (2:58)Technetium 99 Radioisotope Nuclear Medicine: What to expect (2:46 mins)Nuclear Medicine: What to expect Bozeman Biology Radioactive Dating (9 mins)Bozeman Biology Radioactive Dating Carbon-14 Dating (2 mins)Carbon-14 Dating Thyroid tumor Highlight parts of the body for diagnosis PET SCAN: detect tumors, weak spots in arteries
Uses of Radioisotopes Iodine-131 PIB molecule to treat thyroid cancer detect Alzheimers PET scan
Negative Effects of Nuclear Radiation Chernobyl Nuclear Plant Accident
Negative Effects of Radon Radon, a radioactive gas, causes lung cancer Found in regions containing uranium
Ion Charged atom Differs in number of electrons 39Same mass number K+ means lost one electron 19 Same atomic number
ION Charged atom Na + (has lost one electron) O -2 (has gained two electrons) Shown with superscript +/- and number on upper right (can omit number if a 1) What's and Ion? Youtube (6:52)What's and Ion? Youtube
Ions form by gaining or losing electrons
O-2 has gained two electrons Na has lost an e- so it is Na+1
Cation Positive ion Na + Mg +2 Lost electrons Anion Negative ion Cl - O -2 gained electrons
If one electron is… Lost what charge will the ion have? +1 11p+ 11 e- 11p+ 10e-
Which are ions? Cl O -2 Na +1 N 2 Why? O -2 Na +1 Charged atoms (lost or gained electrons) show charges as superscripts
Valence Electrons Outer shell electrons Determines the bonding capacity of an atom
How do electrons arrange themselves in an atom… In the outer electron shells (energy levels)? They are full with 2, 8, 8 Fill inner shell first, then go to next shell out (Outermost shell has the greatest energy) Can you see any pattern how the e- arrange themselves?
Get kinda complicated beyond 2,8,8…so thats all well do for now!
Which electrons determine… The chemical properties of the atom? Outermost shell
If one electron is gained… What charge will the ion have?
If 2 electrons are lost… What charge will the ion have? +2 If two electrons are gained… What charge will the ion have? -2
Filled outer e- shells How many e- fill the first shell (nearest the nucleus)? How many e- fill the next two shells? nucleus
Gain 1 e- or lose 7 e-? If gains 1 e-, then it becomes -1
Gain 7 e- or lose 1 e-? If loses 1 e-, the it becomes +1.
Gain 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
Fill in the chart of e- ElementNumber of e- First shellSecond Third Shell carbon6 lithium3 Sodium11 Oxygen16
Fill in the chart of e- ElementNumber of e- First shellSecond Third Shell carbon624 lithium321 Sodium Oxygen826
How are ion charges determined? Cation = positive (+) ion Anion = negative (-) ion
How are ion charges determined? If lose 1 e- = +1 charge If gain 1 e- = -1 charge If lose 2 e- = +2 charge If gain 2 e- = -2 charge
Periodic Table Hint: You can tell how many electrons are in an atoms outermost shell by just looking at its position on the periodic table!!!!!
Note any pattern of valence electrons (outer shell) as they appear in the periodic table?
+1 +2 share e- in outer shells Ion formed e- in outer shell Full outer e- shells H 8
How many electrons in each shell? (atomic number is given) Carbon oxygen fluorine sodium ,4 2,6 2,7 2,8,1
How many valence electrons? Will these atoms lose or gain e- and how many?
Lose 1 lose O lose 1 share gain 3 lose 1 H+ He Li+ C N-3 Na+
Now lets do the Drawing Atoms Worksheet (and next 4 slides) How the electrons fill their shells (link)How the electrons fill their shells 1 st shell – 1 pair 2 nd shell – e- space far apart, singles, then pair 3 rd shell – e- space far apart, singles, then pair
Bohr Diagram Lets do carbon (6 electrons) 1. Draw a nucleus. 2. Draw the number of rings needed. 3. Start in the first shell- only 2 e-, paired (put next to each other) C Get worksheet
Bohr model electron filling order 2
Are these correct Bohr models?
What errors are at the ?
Now do on the Atomic Structure Worksheet
See the trend of how electrons fill the valence shells Lewis dot structures Octet Rule – electrons fill a shell until its full with 8 electrons Atoms are most stable with a filled outer electron shell
What do we call the forces that… Hold atoms together in a molecule? Chemical bonds …not to be confused with James Bond
Why do atoms bond? To have filled outer electron shells! Atom Heaven ATOM
What is a chemical bond? Attraction between two or more atoms YouTube - ?Ionic and covalent bonding animation?? YouTube - ?Ionic and covalent bonding animation??
Get Bonding Handouts Electronegativities Intermolecular Forces Bonding Reference Sheet
Types of Bonds Intramolecular Within the molecule -Ionic -Covalent Polar Nonpolar Intermolecular Between different molecules Van der Waals London forces Dipoles Hydrogen Bonds
Bonding Covalent share electrons Ionic transfer of electrons (lose or gain)
IONIC BOND lose one or more electrons become (+) gain one or more electrons become (-) The (+) and (-) ions formed now attract each other and form an ionic bond.
Covalent Bonds Polar Covalent Unequal sharing of e- Nonpolar Covalent Equal sharing of e-
Covalent Bonds Click HERE: Polar Covalent Bonding (3 animations)Polar Covalent Bonding Electrons are shared Usually if near the same number of e- in outer shells
Covalent bonding can be shown as: Bohr model Electron-dot Structural Formula
How can covalent bonds be written? Single bond double bond triple bond C-C C=C C=C C:C C::C C:::C 2 e- 4 e- 6 e-
Writing Bonds Each – is equal toEach – is equal to : or : or two electronstwo electrons Single C – C or C:C Double C = C or C::C Triple or C:::C C
Different Ways to Represent Four Common Molecules butane
Making ionic bond in NaCl YouTube - ?Ionic and covalent bonding example?? YouTube - ?Reaction of Sodium & Chlorine (with subtitles)??
SALT = Synonym for an ionic compound Not just NaCl Iron SulfideCopper Sulfate Sodium chloride
LETS REVIEW: Which atoms combine… with other atoms? Ones that do not have filled outer electron shells
REVIEW: What is the driving force to make atoms join with other atoms to form compounds? TO HAVE FILLED OUTER ELECTRON SHELLS
REVIEW: How does an atom… Get a filled outer electron shell? Gaining, losing, or sharing electrons
What do you notice about the ion charge and the subscripts?
Do the Flip-Flop So you can cancel out the (+) and (-)
If there is only one atom, you do not need to write a 1 You can reduce the subscripts if they are the same: Fe +2 O -2 Fe 2 O 2 reduce to FeO
Electronegativity Get Electronegativities handout
Electronegativity Tendency of an atom to attract electrons towards itself and thus the tendency to form negative ions.
Electronegativity The more electronegative atom pulls shared electrons toward its nucleus. NONPOLAR – equal sharing of electrons POLAR – unequal sharing of electrons
Electronegativities H = 2.1 O=3.5 C=2.5 H-H = 0.0 bond pure covalent O-H bond = 1.4 polar ( ) covalent NaCl = 2.1 ionic
Molecule A group of two or more atoms held together by covalent bonds
Whats the difference between Intramolecular and Intermolecular Forces?
Whats the difference? Intermolecular attractions are between one molecule and a neighboring molecule (Van der Waals, hydrogen bonds) USUALLY WEAKER Intramolecular attractions are the forces which hold an individual molecule together (for example, the covalent bonds or ionic bonds). USUALLY STRONG
WHAT IS THE STRENGTH COMPARISON? STRONGEST BOND WEAKEST BOND Covalent Ionic Hydrogen Van der Waals (dipole-dipole London forces) intramolecular
INTERMOLECULAR 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)Intermolecular Forces Youtube
Intermolecular 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.
Hydrogen Bonds: Intermolecular between H and F, O, or N
Where Might you find Hydrogen Bonds? In Water – between O- and H+ In DNA – between bases
Intramolecular: Van der Waals Van der Waals on Gecko Feet (8:22)Van der Waals on Gecko Feet Is the sum of the attractive forces between molecules (but not H-bonds or covalent bonds)
van der Waals Van der WaalsVan der Waals Dispersion ForcesDispersion Forces Temporary dispersion of electrons make temporary charges
Where might you find van der Waals? crystal structures (e. g. the shapes of snowflakes), DNA shape
Intramolecular: (Van der Waal type) Dipole-dipole exists between neutral polar molecules only when they are close together Dipole Forces Bozeman youtube (7:32)Dipole Forces Bozeman youtube Temporary shift of the electrons to make a partial + and a partial - end
Weakest van der Waals: London Dispersion Forces Temporary polarity between nonpolar atoms or molecules All molecules have them at some time Bozeman London Dispersion Forces (5:02)Bozeman London Dispersion Forces
London Dispersion Force London Dispersion Force Animation London Dispersion Force Animation
Disulfide Bonds: Protein Tertiary Structure Disulfide Bond in Tertiary Protein
Disulfide Bonds formed between the side chains of cysteine in a protein SH) to form a disulfide bond (S-S) (Will learn about this in Chapter 3)
THEME 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
How is the emergent property idea apply to a compound and atoms? HINT:
2.9 Chemical Reactions The making and breaking of chemical bonds, leading to changes in the composition of matter.
Chemical Reactions Reactants on the left of the arrow Products on the right of the arrow IDENTIFY: 2Mg(s) + O 2 (g) 2MgO(s) MgO(s) + H 2 O(l) Mg(OH) 2 (s) N 2 (g) + 3H 2 (g) 2NH 3 (g)
Same number of each element on left side as on the right side CH 4 (g) + 2O 2 (g) CO 2 (g) + 2H 2 O (g) ReactantsProducts C = 1 H = 4 O = 4 C = 1 H = 4 O = 4
Signs of a Chemical Reaction Precipitate forms Color Change Gas Forms Temperature change
Chemical Reaction Videos Na and Cl Chemical Rx (52 secs.)Na and Cl Chemical Rx Genie in a Bottle Reaction - Steve Spangler (3:36)Genie in a Bottle Reaction - Steve Spangler Weirdest Chem. Rx in the World (2:52) Mercury(II) thiocyanate Hg(SCN)2Weirdest Chem. Rx in the World The Naked Scientists Videos (MP3)The Naked Scientists Videos
Chemical Reaction Example An iron bar rusts. The iron reacts with oxygen in the air to make rust. 4 Fe + 3 O 2 2 Fe 2 O 3