Ionic Nomenclature Recap Cation is ALWAYS written first. If monoatomic, use the name of the element. If polyatomic, use the name of the polyatomic ion. Anion is ALWAYS written second. If
monoatomic, use -ide as the suffix. If polyatomic, use the name of the polyatomic ion. Covalent Bonding Covalent Bonds What happens to electrons in covalent bond? Electrons Atomic orbitals are combined to form molecular orbitals.
Generally Why? shared between atoms, not given or taken completely. bond between nonmetal and nonmetal. 3 trends need to be taken into account. Electron affinity, Ionization energy, and electronegativity differences between atoms are small. Differences in trends arent large enough for one atom to completely take
away electrons from the other, so electrons are shared. Example: CH4 Moleculea neutral group of atoms that are held together by covalent bonds. Molecular formulashows the types and numbers of atoms combined in a single molecule of a compound. Example: Concept
CH4 check: What is the difference between a molecule and a polyatomic ion? Formation of Covalent Bond Nature favors chemical bondingwhy? Makes the atoms more stable. potential energy is lowered when the atoms are
bonded. Lower energy = more stable. Characteristics of a Covalent Bond Bond lengththe average distance between two bonded atoms. Depends on type of bond: single, double, or triple. Bond Dissociation EnergyThe energy required to break 1 mol of a specific chemical bond (always endothermic). Indicates strength of a bond
In Reactions For endothermic reactions a greater amount of energy is required to break the existing bonds than is released when the new product bonds form. For exothermic reactions more energy is released forming new bonds than is required to break bonds of the reactants. Covalent CompoundsNomenclature RulesBinary
Compounds Element with smaller group # is always given first (similar to cation in ionic bonding). Second element combines prefix with suffix ide. If second element begins with vowel, the o- or a- in the prefix is dropped.
CO Sulfur Trioxide Acids 2 types: Binary Acidscontain H and another element, usually a halogen. 1.) Put hydro- as prefix for H. 2.) Use ic as suffix for second element. ExampleHCl = hydrochloric acid Oxyacidscontain H, O, and a third element (mostly H paired with a polyatomic ion). 1.) Identify anion. 2.) if the anion suffix is ate replace it with ic 3.) if the anion suffix is ite replace it with ous ExampleHNO3 = Nitric Acid Octet Rule
Atoms undergo bonding in order to satisfy the octet rule. Octet rule: Atoms want to be noble gas-like. Diatomic molecule: A molecule in which there are only two atoms. F2, Cl2, Br2, I2, H2, O2, N2, Exceptions to Octet Rule Hydrogenforms only one bond to have two valence electrons. Group 13Has three valence electrons. Tends to form three bonds.
Some elements can form an expanded octet if bound to highly electronegative atoms. Example: SF6 Expanded octet involves empty d orbitals to fit extra electrons. Lewis Structures What are they?? A formula where atomic symbols represent nuclei and inner shell electrons, and dot pairs represent valence and bonded electrons. What
are they used for?? Gives us a way to visualize bonding between atoms Represents Gives where electrons are located relative bond strengths to establish reactivity of molecules. Lewis Structures Six Steps:
1.) Determine types of atoms in molecule. Example: CH3I 2.) Write electron dot notation for each atom. 3.) Determine the total number of valence electros available. 4.) Arrange atoms with LEAST electronegative atom in the center (exception: H), and place one shared pair of electrons between each of the atoms. 5.) Fill in valence shells of atoms with unshared electrons (lone pairs). 6.) Count electrons to make sure all available valence electrons Practice with Lewis Structures Draw the Lewis structures for the
following molecules: NH3 H2S SiH4 PF3 Before we go any further Try the Lewis structure for C2H4. Single and Multiple Covalent Bonds Single Also bond two electrons shared called sigma bond, or bond.
Examples: Double Consists H2 bond four electrons shared of one sigma and one pi bond. Example: O2 Triple bond six electrons shared Consists
of one and two bonds. Example: N2 Lewis structures with multiple bonds Multiple bonds become evident in lewis structures when there are not enough valence electrons after adding lone pairs. Examples: CH2O
CO2 HCN Hybridization Orbitals of similar energy mix to produce new orbitals (hybrids) Example: Carbon in Carbon tetrafluoride Relative Bond Lengths and Strengths Bond lengththe more shared pairs = the shorter the bond.
Single Bond > Double > Triple Strengththe more shared pairs = the stronger the bond. Triple > Double > Single Resonance Structures In molecules with multiple bonds, electrons are delocalized due to shared
orbitals. electrons are delocalized, a single lewis structure cannot account for all of the possible locations of electrons. Only electron locations vary, NEVER atom arrangement. Polarity Based on electronegativity differences. Polar
molecule = uneven distribution of electrons Nonpolar = even distribution Polar Covalent Bonds Identify the bond as polar or nonpolar FF CH OCl CCl HN BF
Non-polar and Polar Covalent Bonds Dipolea molecule that contains both positively and negatively charged regions (unequal sharing of electrons). Nonpolar bonds do not contain a dipole. Identify the dipole in the following molecules NH3 CH3F SF6 BF3
CCl4 Hydrocarbons Hydrocarbons Contain Can 3 = the simplest organic compounds only carbon and hydrogen be straight-chain, branched chain, or cyclic molecules types of straight-chain hydrocarbons Alkanescompletely triple bonds)
End in suffix -ane saturated hydrocarbons (no double or Need to know first ten alkane hydrocarbons CH4 Methane C6H14 Hexane C2H6
Invoice accounting dates greater than 30 days need to be analyze and resolved. ... 7XXX expenditures do not bill on STAT rate sets. June 2017. Grant Task 5 - Identify and resolve Over-the-Limit (OLT) transactions. Run TN_GR19_OLT_CHECK query.
Sensation and Perception ... Size Constancy The tendency to view an object as constant in size despite changes in the size of the retinal image. ... a man's face is seen. If scanned from the right, a woman's figure is...
Belsky, Jay, Deborah Lowe Vandell, Margaret Burchinal, K. Alison Clarke‐Stewart, Kathleen McCartney, and Margaret Tresch Owen. "Are There Long‐Term Effects of Early Child Care?" Child Development. Blackwell Publishing Inc, 23 Mar. 2007. Web. 28 May 2017. Dang, Tran T., and...
I find it useful to issue the command "source("<myfile.R>")", where <myfile.R> is replaced with the filename you want to work with. Remember, that myfile.R must be in the same folder or directory of your R, otherwise type the full directory...
Assertive Mentoring: Each week children will complete assertive mentoring in maths. There are some examples for you to look at on your tables. This test covers 3 areas: - number and place value - multiplication, division and fractions - geometry...
The Continuous Wavelet Transform (CWT) A mathematical representation of the Fourier transform: Meaning: the sum over all time of the signal f(t) multiplied by a complex exponential, and the result is the Fourier coefficients F( ) . ... Discrete Wavelet...
Administração de Marketing KOTLER, Philip; ARMSTRONG, Gary. Princípios de marketing. São Paulo: Pearson Prentice Hall, 2007. Cap. 1. O novo cenário do marketing A nova era digital Talvez a tecnologia mais drástica seja a internet, que conecta indivíduos e negócios...
It will slap things together even if the resulting constant overflows to infinity, or underflows to become zero. 1.#INF is your constant and off we go! Oh, zero, I only need to do a MUL then, yay! There are of...
Ready to download the document? Go ahead and hit continue!