THE CHEMISTRY OF LIFE LIFE IS, EVEN AT THE SMALLEST LEVEL, AN EXTREMELY SOPHISTICATED FORM OF CHEMISTRY. 1A LIVING ENVIRONMENTMURTAUGH

ESSENTIAL QUESTIONS WHAT IS MATTER? WHAT IS AN ATOM? HOW DOES ATOMS FIT INTO THE LEVELS OF ORGANIZATION OF LIFE? WHAT SUBATOMIC PARTICLE IS RESPONSIBLE FOR BONDING? HOW IS THE PERIODIC TABLE OF ELEMENTS ORGANIZED?

VOCABULARY  MATTER: ANYTHING THAT TAKES UP SPACE AND HAS MASS  ATOM: BASIC UNIT OF MATTER  PROTONS- POSITIVELY CHARGED PARTICLES FOUND IN THE NUCLEUS, ATOMIC MASS OF 1.  NEUTRONS- PARTICLES FOUND IN NUCLEUS, NEUTRAL OR NO CHARGE, ATOMIC MASS OF 1.  ELECTRONS- NEGATIVELY CHARGED PARTICLES SURROUNDING NUCLEUS, SOLELY USED IN THE BONDING OF ELEMENTS TO MAKE CHEMICAL COMPOUNDS  NUCLEUS- THE CENTRAL AND MOST IMPORTANT PART OF AN OBJECT

THE NATURE OF MATTER  MATTER – ANYTHING THAT TAKES UP SPACE AND HAS MASS.

ATOMS WHAT ARE ATOMS?  BASIC UNIT OF MATTER (I.E. ALL THINGS ARE MADE OF ATOMS);  MADE OF 3 PARTICLES:  PROTONS  NEUTRONS  ELECTRONS.  INCREDIBLY SMALL (100 MILLION SIDE BY SIDE = 1CM)

ORGANIZATION OF LIFE ATOMS- MAKE UP ALL MATTER (SMALLEST UNIT OF MATTER) CELL- SMALLEST UNIT OF LIFE TISSUE ORGAN ORGAN SYSTEM ORGANISM- MOST COMPLEX PART OF LIFE

STRUCTURE OF AN ATOM  PROTONS- POSITIVELY CHARGED PARTICLES FOUND IN THE NUCLEUS, ATOMIC MASS OF 1.  NEUTRONS- PARTICLES FOUND IN NUCLEUS, NO CHARGE, ATOMIC MASS OF 1.  ELECTRONS- NEGATIVELY CHARGED PARTICLES SURROUNDING NUCLEUS, USED ON THE BONDING OF ELEMENTS TO MAKE CHEMICAL COMPOUNDS

ELEMENTS  A SUBSTANCE IN ITS SIMPLEST FORM, THAT CANNOT BE BROKEN DOWN ANY FURTHER.  MADE OF ONE TYPE OF ATOM.  REPRESENTED BY A SYMBOL ON THE PERIODIC TABLE (1 OR 2 LETTERS). CARBON = C HYDROGEN = H SODIUM= Na

ELEMENTS CONTINUED  92 OF THE ELEMENTS ON PERIODIC TABLE ARE NATURALLY OCCURRING, 25 OF THESE ARE ESSENTIAL FOR LIFE!  4 ELEMENTS MAKE UP 96% OF LIVING MATTER:  CARBON  HYDROGEN  OXYGEN  NITROGEN.

PERIODIC TABLE OF ELEMENTS  AN ARRANGEMENT OF ELEMENTS BASED ON THEIR CHEMICAL PROPERTIES AND ATOMIC NUMBERS  ATOMIC NUMBER: TOTAL NUMBER OF PROTONS; THIS EQUALS THE NUMBER OF ELECTRONS AN ELEMENT HAS BECAUSE AN ELEMENT IS ALWAYS NEUTRAL (THE CHARGES CANCEL EACH OTHER OUT)  MASS NUMBER: TOTAL NUMBER OF PROTONS + (PLUS) NEUTRONS.

6 C Carbon Section 2-1 An Element in the Periodic Table Go to Section:

ESSENTIAL QUESTIONS HOW DOES AN ISOTOPE DIFFER FROM ITS ELEMENT? DO CHEMICAL COMPOUNDS SHARE THE SAME CHEMICAL AND PHYSICAL PROPERTIES OF THE ATOMS THAT FORM IT? HOW ARE CHEMICAL BONDS FORMED? WHAT IS THE DIFFERENCE BETWEEN A COVALENT AND IONIC BOND?

VOCABULARY  ATOMIC NUMBER: TOTAL NUMBER OF PROTONS; THIS EQUALS THE NUMBER OF ELECTRONS AN ELEMENT HAS BECAUSE AN ELEMENT IS ALWAYS NEUTRAL (THE CHARGES CANCEL EACH OTHER OUT)  MASS NUMBER: TOTAL NUMBER OF PROTONS + (PLUS) NEUTRONS.  ISOTOPE: ATOMS WITH THE SAME NUMBER OF PROTONS, BUT DIFFERENT NUMBERS OF NEUTRONS  COMPOUNDS: SUBSTANCES FORMED BY THE CHEMICAL COMBINATION OF 2 OR MORE ELEMENTS.  VALANCE ELECTRONS: OUTER MOST ELECTRONS USED ON THE CHEMICAL BONDING OF ATOMS  COVALENT: A BOND FORMED WHEN VALENCE ELECTRONS ARE SHARED BETWEEN 2 ATOMS.  IONIC: FORMED WHEN ELECTRONS ARE GAINED OR LOST FROM ONE ATOM TO ANOTHER.

ISOTOPES ATOMS WITH THE SAME NUMBER OF PROTONS, BUT DIFFERENT NUMBERS OF NEUTRONS. SAME CHEMICAL PROPERTIES. MORE UNSTABLE THEN ORIGINAL ELEMENT USED FOR SCIENTIFIC DATING, MEDICAL IMAGINING, CANCER TREATMENTS, SMOKE DETECTORS, AND IN DNA FINGERPRINTING

Nonradioactive carbon-12Nonradioactive carbon-13Radioactive carbon-14 6 electrons 6 protons 6 neutrons 6 electrons 6 protons 8 neutrons 6 electrons 6 protons 7 neutrons Figure 2-2 Isotopes of Carbon Go to Section: Isotopes

CHEMICAL COMPOUNDS COMPOUNDS: SUBSTANCES FORMED BY THE CHEMICAL COMBINATION OF 2 OR MORE ELEMENTS. CHEMICAL FORMULA (SHORTHAND) H 2 ONaCl

COMPOUNDS (CONT.) PHYSICAL & CHEMICAL PROPERTIES OF COMPOUNDS DIFFER FROM THE ELEMENTS THAT COMBINE TO FORM THE COMPOUNDS. H 2 O LIQUID AT STANDARD ROOM CONDITIONS. H IS GAS S.R.C. O IS GAS S.R.C.

WHY DO COMPOUNDS FORM? OUTERMOST ENERGY LEVELS MUST BE “FILLED” WITH ELECTRONS (VALENCE ELECTRONS.) 1 ST ENERGY LEVEL FILLED = 2 ELECTRONS HYDROGEN (H)HELIUM (HE) 2 ND, 3 RD, 4 TH, ETC. ENERGY LEVEL FILLED = 8 ELECTRONS. CARBON (C)OXYGEN (O) THIS MAKES THE COMPOUND MORE STABLE.

CHEMICAL BONDING COVALENT: A BOND FORMED WHEN VALENCE ELECTRONS ARE SHARED BETWEEN 2 ATOMS. FORMS MOLECULES EXAMPLE: H 2 O IONIC: FORMED WHEN ELECTRONS ARE GAINED OR LOST FROM ONE ATOM TO ANOTHER. FORMS IONS EXAMPLE: NaCl

COVALENT BONDING

Sodium atom (Na) Chlorine atom (Cl)Sodium ion (Na + )Chloride ion (Cl - ) Transfer of electron Protons +11 Electrons -11 Charge 0 Protons +17 Electrons -17 Charge 0 Protons +11 Electrons -10 Charge +1 Protons +17 Electrons -18 Charge -1 Section 2-1 Figure 2-3 Ionic Bonding Go to Section: Ionic Bonding

Sodium atom (Na)Chlorine atom (Cl)Sodium ion (Na + )Chloride ion (Cl - ) Transfer of electron Protons +11 Electrons -11 Charge 0 Protons +17 Electrons -17 Charge 0 Protons +11 Electrons -10 Charge +1 Protons +17 Electrons -18 Charge -1 Go to Section: Ionic Bonding

WATER 1. WORKING WITH A PARTNER, MAKE A LIST OF TEN THINGS THAT HAVE WATER IN THEM. 2. EXCHANGE YOUR LIST FOR THE LIST OF ANOTHER PAIR OF STUDENTS. DID YOUR LISTS CONTAIN SOME OF THE SAME THINGS? DID ANYTHING ON THE OTHER LIST SURPRISE YOU? 3. DID EITHER LIST CONTAIN ANY LIVING THINGS?  __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ __________________________ Interest Grabber continued Go to Section:

ESSENTIAL QUESTIONS WHY IS WATER SUCH AN IMPORTANT MOLECULE? WHAT IS pH? WHAT IS THE DIFFERENCE BETWEEN AN ACID AND BASE? WHAT IS AN INDICATOR?

VOCABULARY  COHESION : ATTRACTION BETWEEN MOLECULES OF THE SAME SUBSTANCE.  ADHESION: ATTRACTION BETWEEN MOLECULES OF DIFFERENT SUBSTANCES.  MIXTURE: ANY COMBINATION OF SUBSTANCES THAT ARE PHYSICALLY COMBINED WITHOUT FORMING NEW CHEMICAL BONDS.  SOLVENT: USUALLY A LIQUID, THAT MAKES UP THE BULK OF A SOLUTION.  SOLUTE: SUBSTANCE DISSOLVED IN A SOLVENT.  SOLUTIONS: ANY HOMOGENEOUS MIXTURE, USUALLY REFERRING TO MIXTURES THAT ARE LIQUID.

VOCABULARY  PH: THE MEASUREMENT OF THE CONCENTRATION OF HYDROGEN IONS IN SOLUTION.  ACID : ANY COMPOUND THAT HAS OR RELEASES H+ IONS.  BASE: ANY COMPOUND THAT HAS OR RELEASES OH- (HYDROXIDE) IONS.  INDICATOR: ANY SUBSTANCE USED TO ASSIST IN THE CLASSIFICATION OF ANOTHER SUBSTANCE  BUFFERS: WEAK ACIDS OR BASES THAT REACT WITH STRONG ACIDS OR BASES TO CONTROL pH FLUCTUATIONS

WATER  THE WATER MOLECULE IS SAID TO BE POLAR COVALENT – THERE IS A UNEVEN SHARING OF ELECTRONS BETWEEN H AND O  O HAS MORE PROTONS THAN H AND THEREFORE HAS A GREATER PULL ON THE ELECTRONS FROM H, LEAVING H WITH A SLIGHTLY POSITIVE CHARGE AND O WITH A SLIGHTLY NEGATIVE CHARGE  THE RESULT IS A POLAR MOLECULE, LIKE A WEAK MAGNET

WATER (CONT.)  HYDROGEN BONDS ARE FORMED WHEN THE ATTRACTION BETWEEN THE H ATOM ON 1 MOLECULE IS ATTRACTED TO ANOTHER ATOM THAT HAS A SLIGHTLY NEGATIVE CHARGE  WEAK COMPARED TO IONIC AND COVALENT BONDS  HYDROGEN BONDING EXPLAINS THE PROPERTIES OF WATER – COHESION AND ADHESION

PROPERTIES OF WATER  COHESION – ATTRACTION BETWEEN MOLECULES OF THE SAME SUBSTANCE.  EX) SURFACE TENSION OF WATER  ADHESION – ATTRACTION BETWEEN MOLECULES OF DIFFERENT SUBSTANCES.  EX) “CUPPING” OF WATER ON EDGE OF GRADUATED CYLINDER, THE MENISCUS

 CHEMICAL REACTIONS – THE COMBINATION OF TWO OR MORE ELEMENTS FORMING A DIFFERENT PRODUCT. 6CO2 + 12H2O  C6H12O6 + 6O2 + 6H2O  MIXTURE – ANY COMBINATION OF SUBSTANCES THAT ARE PHYSICALLY COMBINED WITHOUT FORMING NEW CHEMICAL BONDS. EX. CAKE BATTER

 SOLVENT – USUALLY A LIQUID, THAT MAKES UP THE BULK OF A SOLUTION.  SOLUTE – SUBSTANCE DISSOLVED IN A SOLVENT.  SOLUTIONS – ANY HOMOGENEOUS MIXTURE, USUALLY REFERRING TO MIXTURES THAT ARE LIQUID.

 SUSPENSION – A MIXTURE THAT SEPARATES AFTER STANDING. EX. ITALIAN SALAD DRESSING OIL AND VINEGAR)  COLLODIAL SUSPENSIONS/DISPERSIONS – PARTICLES IN THE SOLVENT ARE TOO LARGE TO BECOME HOMOGENEOUS, BUT TOO SMALL TO SETTLE OUT. EX. WHIPPED CREAM, MILK, MAYO, SODA.

pH- THE MEASUREMENT OF THE CONCENTRATION OF HYDROGEN IONS IN SOLUTION. ACID – ANY COMPOUND THAT HAS OR RELEASES H+ (HYDROGEN) IONS. HCl  H+ + Cl- BASE – ANY COMPOUND THAT HAS OR RELEASES OH- (HYDROXIDE) IONS. NaOH  Na+ + OH-

Oven cleaner Bleach Ammonia solution Soap Sea water Human blood Pure water Milk Normal rainfall Acid rain Tomato juice Lemon juice Stomach acid Neutral Increasingly Basic Increasingly Acidic Section 2-2 pH Scale Go to Section:

 NEUTRALIZATION REACTIONS: A REACTION THAT COMBINES AN ACID AND A BASE TO PRODUCE A SALT AND WATER. EX) HCl + NaOH > NaCl + H 2 O

 INDICATORS: ANY SUBSTANCE USED TO ASSIST IN THE CLASSIFICATION OF ANOTHER SUBSTANCE LITMUS PAPER: BLUE PAPER TESTS FOR ACIDS (TURNING RED SHOWS A POSITIVE RESULT) RED PAPER TESTS FOR BASES (TURNING BLUE SHOWS A POSITIVE RESULT)  BUFFERS: WEAK ACIDS OR BASES THAT REACT WITH STRONG ACIDS OR BASES TO CONTROL pH FLUCTUATIONS (HELP MAINTAIN HOMEOSTASIS IN HUMANS)