Biochemistry Part 2

Biochemistry Part 2Bonding, Isotopes, and RadioactivityRecapAtomic structureValence electronsHappy atoms are full atoms (8 ve or 2 ve)How do we make them happy??? STEALING or SHARING valence shell electrons to have a complete ringremember the Samaras?

Ionic BondsAtoms become IONS by losing or gaining electronsWhat is the charge of an electron?Sooothey are losing or gaining a NEGATIVE charge

Covalent BondsSHARING of electronsVal. Electrons spend their time around both atoms involved in the bondNOT always equally shared, but still sharedTwo Types of Bonds Ionic CompoundsIonsA POSITIVELY or NEGATIVELY charged particleFormed by gaining or losing electrons in an effort to become stableAtom that lose one or more electron(s) POSITIVELY charged..CA+IONSAtom that gains one or more electron(s)ANIONS

STEALING e-Which atoms become ions?Which ever are veryyyyy close to being happyThey either have to lose or gain one or two electrons to have a complete outer ringRemember, atoms are LAZY, they want to do as little work as possible to be happyGroups 1A and 2A will lose e- and become +1 or +2 ca+ions (+)Groups 6A and 7A greedy little suckers that will steal e- to become -1 or -2 anions (-)

Formation of Ionic CompoundsOpposites attractpositive ion finds an equally negative ion and they are hooked! (bonded)..its an IONIC BOND!!!

Charges cancel out and now we have a neutral (zero charge) Ionic Compound

When naming Ionic CompoundsSay the ca+ion first, then the anionAdd the suffix ide to the anionEx. Sodium and chlorine formNa+ and Cl-You say Sodium chlorideCovalent CompoundsNot greedythey would rather shareTheir outer rings are about half way fullGroups 3,4 and 5The # of bonds an atom can form is equal to the number of valence electrons it NEEDS to be happyOxygen has___v.e.it needs___to be happy, so it can make ____ bonds.

Covalent Bonds make2 or More atoms covalently bonded make a compound called a MOLECULESharing of 2 e- b/t 2 atoms single bond (pretty strong)Sharing of 4 e- b/t 2 atoms double bond (stronger hold)Sharing of 6 e- b/t 2 atoms triple bond (really strong!)

7 Diatomic MoleculesDi- means..2Atomic meansReferring to atomsMoleculesCovalently bonded atomsPut it together and what do you get:2 atoms of the same element that are covalently bonded to EACHOTHEROccurs naturally in NatureBr2 I2 N2 Cl2 H2 O2 F2BrINClHOF!!!RecapWhen we change # of protons we getA different elementWe dont want to change this!When we change # of electrons we getIONS! Cations + LOSE an electronAnions Gain an electronWhen we change the # of neutrons we get

Atoms with the same atomic number but with different atomic masses are called isotopesChanging the # of neutrons in an atom will affect theMASS NUMBER= protons + neutronsIsotopes of an element have the same # of p+ and e-so they behave the same CHEMICALLYThe average of all the mass #s of the isotopes of an element give us that decimal on the periodic table (Average Atomic Mass)

ISOTOPES!

Radioactive IsotopesAs the difference b/t p+ and n. in the nucleus increases, the nucleus becomes more unstableWhen p=n , nucleus is stableWhen n>p, nucleus is unstableNucleus will give off tiny amounts of energy to become stable (protons or neutrons)Radiation=energyRadioactive=when something gives off energy

Isotopes of the Element Potassium with a Known Natural AbundanceMass # Natural Abundance Half-life 39 93.2581% Stable 40 0.0117% 1.26510+9 years 41 6.7302% Stable

Isotopes continuedRadiation can be dangerous in large amounts but in small amounts it can be useful in scienceGeology-determine age of fossils and rocksMedicine-treat cancer and detect cell processes (tracers)PET scans, CT scans, MRICommercial-kill bacteria that spoils certain foods

Mm Isotope Discovery Lab

New Discovery!!!You and your research team have discovered a new elementMmMm is an essential element in the human dietThere are three naturally occurring isotopes of the element Mm Atomic Number of Mm is 30Your teams goal is to determine the average atomic mass of the element Mm by determining the percent abundance of each naturally occurring Mm isotopeYou have already determined the masses of each of the three different Mm isotopes:

IsotopeAtomic #Mass # (amu)Neutrons #colorMm-R3065 amuredMm-Y3066 amuyellowMm-B3069 amubrownCalculationsPercent Abundance of isotope Mm-R=(Total # of Mm-R in nature/ Total # of all Mm-isotopes in nature) x 100%Percent Abundance of isotope Mm-B=(Total # of Mm-B in nature/ Total # of all Mm-isotopes in nature) x 100%Percent Abundance of isotope Mm-Y=(Total # of Mm-Y in nature/ Total # of all Mm-isotopes in nature) x 100%Mass Contribution of each isotope:(amu of Mm isotope) x (percent abundance of Mm isotope in nature)Average Atomic Mass= [(mass contribution of Mm-R) + (mass contr. of Mm-B) + (mass contr. of Mm-Y)] Show ALL CalculationsTake Pictures of Set upRecord all procedures

HomeworkComplete Lab Report For Isotope LabSee lab report guidelinesExtra Credit:Make A Creative Periodic Table Element Box for your New Element.Be sure to include all your information you gathered from your extensive research!Atomic NumberAverage Atomic MassChemical SymbolBE CREATIVE!