7.6 Molecular Structure and Polarity | Chemistry Learning Objectives By the end of this section, you will be able to: Predict the structures of small molecules using valence shell electron pair repulsion (VSEPR) theoryExplain the concepts of polar covalent bonds and molecular polarityAssess the polarity of a molecule based on its bonding and structure Thus far, we have used two-dimensional Lewis structures to represent molecules. Valence shell electron-pair repulsion theory (VSEPR theory) enables us to predict the molecular structure, including approximate bond angles around a central atom, of a molecule from an examination of the number of bonds and lone electron pairs in its Lewis structure. VSEPR theory predicts the arrangement of electron pairs around each central atom and, usually, the correct arrangement of atoms in a molecule. As a simple example of VSEPR theory, let us predict the structure of a gaseous BeF2 molecule. Figure 2. Electron-pair Geometry versus Molecular Structure Figure 4. Example 1 Figure 8. Answer: Example 2 Example 3
PCR Primers are short pieces of DNA that are made in a laboratory. Since they're custom built, primers can have any sequence of nucleotides you'd like. In a PCR experiment, two primers are designed to match to the segment of DNA you want to copy. Through complementary base pairing, one primer attaches to the top strand at one end of your segment of interest, and the other primer attaches to the bottom strand at the other end. In most cases, 2 primers that are 20 or so nucleotides long will target just one place in the entire genome. Primers are also necessary because DNA polymerase can't attach at just any old place and start copying away. DNA Polymerase is a naturally occurring complex of proteins whose function is to copy a cell's DNA before it divides in two. The DNA polymerase in our bodies breaks down at temperatures well below 95 °C (203 °F), the temperature necessary to separate two complementary strands of DNA in a test tube.
Getting your practical programme together - OSC IB Blogs Hopefully, by now you will have had time to reflect on the new course and start thinking about your practical programme (PSOW). It is my intention of this blog post ot give you some ideas of things you can add to your PSOW. Are you aware of the ten mandatory labs / skills that you are expected to teach your students? Hang on, I hear you say – you said ten mandatory skills – but I can count twelve.
Gene Delivery: Tools of the Trade Genes can be delivered into a group of cells in a patient's body in two ways. The first, called in vivo (in VEE-voh), is to inject the vector directly into the patient, aiming to target the affected cells. The second, called ex vivo (ex VEE-voh), is to deliver the gene to cells that have been removed from the body and are growing in culture. After the gene is delivered, integration and activation are confirmed, and the cells are put back into the patient. Ex vivo approaches are less likely to trigger an immune response, because no viruses are put into patients. Bone marrow contains stem cells that give rise to many types of blood cells. 3-D Biological Molecules Listed below are links to pages containing 3-dimensional displays of models of molecules of Biological interest. These may be moved in an intuitive way using the computer mouse or touchscreen. In the explanatory text are links which highlight features of the molecule or give extra information. These units are now based on HTML5 and javascript, so they should be more accessible from most PCs and tablets, including iPads. On Windows PCs, best results are obtained using Firefox or Chrome. Some files have been converted to be compatible with mobiles and tablets which have a narrower screen, incompatible with the display format used on desktop/laptop machine. Please let me know if these are (or are not) working on your system! More molecules to be added in the near future Web references and useful websites The Protein Data Bank (PDB; ) is the single worldwide archive of structural data of biological macromolecules, now containing more than 100,000 structures.
Letöltés « E-Animations Zrt. Kérjük, figyelmesen olvassa el az alábbi telepítése útmutatót. Tömörítse ki a letöltött Genom demot az Ön által kiválasztott mappába. Ügyeljen arra, hogy ehhez egy külön mappát hozzon létre.Futtassa a Genom.exe-t. Segítség a kezdéshez: A Genom elindulása után a szürke háttéren való kattintással hívható elő a menü.Újra a háttérre kattintva a menü eltűnik.Kattintson rá és tartsa nyomva a menü középső részét, majd húzza a kívánt helyre a menüt.Húzza a menüt az ablak bármely szélére, így a menü nem fog eltűnni. Tippek: Az animációk feliratos változatát az animáció képe felett megjelenő animáció címére kattintva játszhatja le. Figyelem!
CORE_Chapter Fourteen - Gas Phase, Solubility, Complex Ion Equilibria NO2N2O4 Equilibrium This animation shows the effect of change the volume of a gas phase equilibrium mixture where the numbers of reactant and product molecules are different. CaO CaCO3 Equilibrium This animation shows a solid and gas equilibrium system and the effect adding additional solid on the position of the equilibrium. Energy of Activation This animation shows the change in the number of molecules with energy greater than the energy of activation as the temperature increases. H2 I2 Equilibrium This animation shows the effect of change the volume of a gas phase equilibrium mixture where the numbers of reactant and product molecules are the same. N2 O2 Equilibrium This animation shows a gas phase equilibrium system. Solubility of AgCl This animation shows the equilibrium between an ionic solid and the ions in solution for slightly soluble AgCl. Ksp of Mg(OH)2 and Ca(OH)2 Lab Document This is the document for the determination of the Ksp of Ca(OH)2 and Mg(OH)2 lab.
IB Biology/Chemistry: Error/Uncertainty IB Chemistry,Uncertainty, Error Analysis, Standard Deviation Uncertainty Calculation for Rate and Concentration of reaction. Rate = 1/time, Time for X to disappear. ( Iodine Clock Reaction) 3 Methods for Uncertainty Calculation for Rate (0.10M) KI. Average time is (5.28 + 4.75 + 4.47) / 3 = 4.83 1) % Uncertainty Method Uncertainty time = Uncertainty stop watch + reaction time, ( 0.01 + 0.09 ) = ( 0.10 )Time = 4.83 ±( 0.10 ) 2) Max-min range Method Uncertainty time = (Max time - Min time)/2, = ( 5.28 - 4.47 )/2 = 0.41Time = 4.83 ±0.41 1) %Uncertainty Method Uncertainty time = (4.83 ± 0.10) Rate = 1/ time, 1/4.83 = 0.207 2) Max-min range Method Uncertainty time = ( 4.83 ± 0.41) Rate = 1/time, 1/4.83 = 0.207 %Uncertainty time = (0.1/4.83) x100 %=2.07 %Uncertainty Rate = %Uncertainty time %Uncertainty Rate = 2.07% Rate = 0.207 ± 2.07 % Rate = 0.207 ± 0.004 % Uncertainty time = (0.41/4.83) x 100% = 8.48% % Uncertainty Rate = % Uncertainty time %Uncertainty Rate = 8.48% Rate = 0.207 ± 8.48% Rate = 0.207 ± 0.017 1.
mplex ions - colour What about non-transition metal complex ions? Non-transition metals don't have partly filled d orbitals. Visible light is only absorbed if some energy from the light is used to promote an electron over exactly the right energy gap. Non-transition metals don't have any electron transitions which can absorb wavelengths from visible light. For example, although scandium is a member of the d block, its ion (Sc3+) hasn't got any d electrons left to move around. In the zinc case, the 3d level is completely full - there aren't any gaps to promote an electron in to. Tetrahedral complexes Simple tetrahedral complexes have four ligands arranged around the central metal ion. The net effect is that when the d orbitals split into two groups, three of them have a greater energy, and the other two a lesser energy (the opposite of the arrangement in an octahedral complex). The factors affecting the colour of a transition metal complex ion The nature of the ligand The list shows some common ligands.