For SC180 Unit 5, a bonding diagram analysis built on Lewis structures of CO2, SO2, BF3 and NH3, with each shape argued from the electron domains its central atom holds. Searches like "sc 180 unit 5 assignment example", "sc180 unit 5 sample" and "sc180 unit 5 example" land here.
What a finished SC180 Unit 5 bonding diagram analysis looks like
Four diagrams, each with its valence electron total written above it: 16 for CO2, 18 for SO2, 24 for BF3 and 8 for NH3. Carbon dioxide has two double bonds and no lone pair on carbon, so two electron domains sit 180 degrees apart and the molecule is linear and nonpolar despite its polar bonds. Sulfur dioxide carries the same two bonded atoms plus a lone pair on sulfur, giving three domains, a bent shape near 119 degrees and a net dipole. The second pair repeats the test: boron trifluoride, three domains and no lone pair, is trigonal planar and nonpolar, while ammonia, four domains including one lone pair, is trigonal pyramidal near 107 degrees. Formal charges appear for SO2, +1 on sulfur and -1 on the single-bonded oxygen, with both resonance forms drawn.
How a SC180 Unit 5 example is structured
The analysis typically runs as a short method section followed by one worked diagram per molecule and a comparison paragraph for each pair. The method states the counting procedure once: total valence electrons, a skeleton with the least electronegative atom other than hydrogen at the center, bonding pairs placed, octets completed on outer atoms, remaining electrons on the center. Electron domain geometry and molecular shape are kept as two separate lines under every diagram. Each pair's comparison paragraph names the single difference, a lone pair, and argues its effect on angle and polarity. Boron gets a sentence acknowledging its incomplete octet as an accepted exception rather than a drawing error. Closing the analysis, a summary table carries columns for domains, lone pairs, geometry, shape, approximate angle and polarity, so the four cases read side by side.
Electron count above every drawing
Each diagram starts from its valence total, so a reader can confirm that 18 electrons in SO2 account for the bonds, the lone pair on sulfur and every lone pair on oxygen.
Geometry and shape on separate lines
Electron domain geometry describes where all domains point; molecular shape describes the atoms alone. Writing both under each structure makes ammonia readable as tetrahedral domains around a pyramidal molecule.
Pairs that isolate one variable
CO2 and SO2 differ by a lone pair, and so do BF3 and NH3. Choosing pairs this way lets the analysis attribute each bend to a single cause instead of listing shapes.
Polarity argued from geometry
Polar bonds cancel in linear CO2 and planar BF3 and fail to cancel in bent SO2 and pyramidal NH3, which the analysis shows with bond dipole arrows added to each sketch.
Formal charge settles the SO2 drawing
Charges of +1 and -1 in each resonance form justify the structure chosen, and the analysis adds that the real molecule is an average of both forms, with equal sulfur-oxygen bond lengths.
Where marks go in SC180 Unit 5
The heaviest deductions come from shapes named without the domain count that forces them, bent for SO2 with no lone pair drawn on sulfur. Confusing electron domain geometry with molecular shape costs the next share, as when NH3 is called tetrahedral as though its lone pair were an atom. Electron counts off by two, usually from a forgotten lone pair or an ion's charge ignored, send every later step astray. Polarity answers lose credit when they rest only on whether bonds are polar, which makes CO2 polar by mistake. Boron drawn with a double bond to reach an octet, without comment, invites a note on formal charge. Missing resonance forms for SO2, bond angles quoted for the wrong geometry and dipole arrows pointing toward the less electronegative atom make up the remaining deductions in most sections.
Get a SC180 Unit 5 example written to your instructions
Send the molecules or ions your SC180 Unit 5 prompt lists, together with the drawing conventions your instructor set and the rubric. Each structure is drawn and argued the same way, electron count, domains, shape and polarity, with a comparison wherever the set invites one. Back inside 24-48h, with the first analysis free.
SC180 Unit 5 questions, answered
Why is CO2 nonpolar when its bonds are polar?
Because its shape cancels them. Carbon dioxide is linear, so the two carbon-oxygen bond dipoles point in exactly opposite directions and sum to zero. Sulfur dioxide has polar bonds too, but its lone pair bends the molecule, so the dipoles no longer cancel and a net dipole remains. Polarity depends on bonds and geometry together, never on bonds alone.
What is the difference between electron geometry and molecular shape?
Electron geometry counts every electron domain around the central atom, bonds and lone pairs alike. Molecular shape describes only where the atoms sit. Ammonia has four domains, so its electron geometry is tetrahedral, but one domain is a lone pair, so the shape is trigonal pyramidal. Many SC180 rubrics ask for both, and naming only one is a common deduction.
Is it wrong that boron in BF3 has only six electrons?
No. Boron is one of the standard exceptions to the octet rule, and BF3 is normally drawn with three single bonds and six electrons around boron. Some texts discuss a double-bonded resonance form, but formal charges favor the single-bonded structure. A sentence acknowledging the exception shows the drawing was deliberate rather than incomplete.