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  • Molecular geometry of ethylene: H–C–H and H–C–C angles?

    Ethylene is planar with an overall trigonal planar geometry around each carbon, the hydrogen–carbon–hydrogen angle is about one hundred seventeen point four degrees and the hydrogen–carbon–carbon angle is about one hundred twenty one point three degrees, both close to the ideal one hundred twenty degrees for sp two hybridization.

    Think of each carbon in ethylene like a flat triangle where the carbon sits in the middle and three atoms spread out around it to make space, so the shape is flat like a sheet of paper; the double bond between the carbons holds those two carbons and their attached hydrogens all in the same plane, and because each carbon uses sp two hybrid orbitals, the bond angles end up near one hundred twenty degrees, with the measured hydrogen–carbon–hydrogen angle around one hundred seventeen point four degrees and the hydrogen–carbon–carbon angle around one hundred twenty one point three degrees.

    Students often assume double bonds always force perfect one hundred twenty degree angles, but small differences arise from the actual positions of hydrogen atoms and the double bond electron density pulling slightly more on adjacent atoms, and the quick fix is to remember that experimental angles can deviate a little from the idealized value; another common mistake is picturing ethylene as three dimensional like methane instead of flat, and you can avoid that by drawing the carbons and all substituents on the same plane; some learners mix up angle labels so always double-check whether you are measuring H–C–H or H–C–C to avoid swapping the numbers.

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    Ethylene Geometry: H–C–H and H–C–C Angles

    1. Carbon centers are trigonal planar
    2. Atoms lie in the same plane
    3. Double bond keeps carbons flat
    4. sp2 hybridization gives ~120° angles
    5. H–C–H ≈117.4° and H–C–C ≈121.3°

    Common Mistakes with Ethylene Geometry

    1. Assuming perfect 120° angles
    2. Picturing ethylene as 3D
    3. Mixing up angle labels

    ethylene, moleculargeometry, sp2hybridization, bondangles, HCHangle, HCCangle, planarmolecules, organicchemistry, doublebond, VSEPR

  • How are C–H bonds formed in ethylene and how many?

    Each carbon in ethylene uses its remaining sp two orbital to overlap with a hydrogen one s orbital, forming a sigma carbon hydrogen bond, and there are four carbon hydrogen sigma bonds in total, two on each carbon.

    Think of each carbon atom like a three‑armed tool after it makes the bond to the other carbon and sets up a leftover p orbital for the double bond; those three arms are the sp two orbitals and two of them point toward hydrogen atoms so they can link up. A hydrogen atom brings a single one s orbital and when that one s overlaps head‑on with the carbon sp two orbital they make a strong sigma bond, which is the simple stick holding them together. Because each carbon has two of those sp two orbitals available for hydrogen, each carbon makes two carbon hydrogen sigma bonds, and with two carbons in the molecule that gives four carbon hydrogen sigma bonds altogether. The unhybridized p orbital on each carbon sits above and below the bond axis and overlaps side‑by‑side with the other carbon’s p orbital to form the pi part of the double bond, but that pi bond does not involve hydrogen.

    Students often think the pi bond uses the same orbitals that bond to hydrogen, which is not true because the pi bond comes from separate unhybridized p orbitals, so keep hybrid and unhybridized orbitals distinct. Some assume each carbon could use pure p orbitals to bond to hydrogen, but hydrogen only matches well with the head‑on sp two orbital for a sigma bond, so picture hydrogen meeting the sp two lobe straight on. Others confuse the count and forget to double the per‑carbon bonds, so remember two hydrogens per carbon gives four carbon hydrogen bonds total.

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    Ethylene C–H Bond Formation Explained

    1. Carbon has three sp2 orbitals
    2. Two sp2 orbitals bond to hydrogen
    3. Hydrogen uses a 1s orbital
    4. Sigma bonds form by head-on overlap
    5. Each carbon makes two C–H bonds
    6. Total of four C–H bonds

    Common Mistakes in Ethylene Bonding

    1. Believing pi bond uses hydrogen orbitals
    2. Thinking carbons use pure p orbitals
    3. Forgetting to count two H per carbon

    ethylene, C–Hbonding, sp2hybridization, sigmabond, piorbital, organicchemistry, molecularstructure, bondingbasics, chemicalbonds, orbitaloverlap

  • Where are σ and π electrons located in a C=C bond?

    Electrons in the sigma bond sit along the line connecting the two carbon nuclei, and electrons in the pi bond occupy regions above and below that line.

    Think of two carbon atoms as two people holding hands; the sigma bond is like their linked hands right between them, with the shared electrons concentrated along the straight line connecting the centers of the two atoms, which we call the internuclear axis. The pi bond is like two balloons, one above the hands and one below, where electron density sits in lobes outside the line between the nuclei instead of directly between them. The sigma electrons are closer to the space between the nuclei and help hold the atoms together strongly along that axis, while the pi electrons are spread out over the sides and are more exposed to interactions with other atoms or reagents. Together they make the double bond stronger than a single bond, but the pi part is more chemically reactive because its electrons are more accessible.

    A common mistake is picturing both pairs of electrons as sitting on the same line, which ignores the sideways overlap that makes the pi lobes above and below the axis; remember the pi density is not between the nuclei. Another error is thinking the pi electrons are weaker because they are farther from the axis, when actually the sigma is stronger at holding atoms together along the axis while the pi contributes to strength and reactivity in a different way; keep in mind they play complementary roles. A third misconception is assuming the pi electrons are free to move everywhere; they are delocalized only when the molecule allows conjugation, so check the bonding pattern to know if pi density spreads.

    For more videos and resources about electron distribution and bonding, check out our website w w w dot gumball degree dot com.

    C=C Electron Density: σ vs π Locations

    1. Sigma electrons along internuclear axis
    2. Pi electrons above and below axis
    3. Sigma closer between nuclei
    4. Pi electrons more exposed
    5. Pi more chemically reactive

    Common Mistakes About σ and π Electrons

    1. Thinking both electrons lie on axis
    2. Assuming pi electrons are weaker
    3. Believing pi electrons always delocalize

    sigmaelectrons, pielectrons, doublebond, C=C, electrondensity, bonding, organicchemistry, molecularorbitals, chemicalreactivity, bondstructure

  • How is a C=C formed between two sp2 carbons?

    The carbon–carbon double bond between two sp two carbons is made of an sp two–sp two sigma bond from head-on overlap of sp two orbitals plus a pi bond from sideways overlap of the unhybridized p orbitals, and together they share four electrons between the carbons.

    Think of each carbon as having three sp two orbitals that lie in one flat plane and one leftover p orbital that stands straight up; when two such carbons come together the sp two orbitals on each carbon point at each other and overlap head on to make a strong sigma bond that holds the atoms along the line between them, while the unhybridized p orbitals, one on each carbon, sit parallel and overlap sideways above and below the sigma bond to make the pi bond, so the sigma gives the main bond framework and the pi adds extra bonding and restricts rotation, and the four shared electrons occupy these two bonding interactions giving the double bond its strength and shorter length.

    A common mistake is thinking both bonds are identical when actually the sigma is stronger and the pi is weaker and more reactive, and the fix is to remember sigma is head on and pi is sideways; another misconception is imagining free rotation around a double bond, but the pi overlap prevents rotation unless the pi is broken so students should picture the p orbitals aligned to keep the bond rigid; some learners also forget there are four shared electrons total, not two plus two separated, so count the electrons in both sigma and pi together to avoid that error.

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    C=C Formation Between Two sp2 Carbons

    1. sp2 orbitals lie in one plane
    2. one unhybridized p orbital stands up
    3. sp2 orbitals overlap head on
    4. sigma bond holds atoms together
    5. p orbitals overlap sideways
    6. pi bond restricts rotation
    7. four electrons occupy both bonds

    Common Mistakes in C=C Bonding

    1. Treating sigma and pi as identical
    2. Assuming free rotation around double bond
    3. Forgetting total of 4 shared electrons

    sp2 doublebond sigma pi carboncarbon hybridization organicchemistry porbitals bonding molecularstructure

  • What is the spatial arrangement of sp2 and p orbitals?

    The three sp two hybrids lie in a single plane with one hundred twenty degree angles between them, and the unhybridized p orbital is perpendicular to that sp two plane.

    Think of an sp two carbon like a person standing on a flat floor with three arms stretched out evenly so each arm is the same distance from the others; those three arms are the sp two orbitals lying flat in the same plane and pointing away from each other at about one hundred twenty degrees, making a flat triangular arrangement. The leftover p orbital is like a flagpole sticking straight up from the floor at a right angle to those arms, sitting above and below the plane. When atoms bond, the flat sp two orbitals form sigma bonds in that plane, and the upright p orbital can overlap side to side with another p to form a pi bond, which needs the perpendicular orientation. Picture the plane as a tabletop and the p orbital as a pencil standing on it to make the orientation clear.

    Students often imagine all orbitals pointing toward electrons instead of thinking about the directional shapes, so remember orbitals are regions in space with specific directions and angles; draw the plane and pencil to visualize this. Another common mistake is picturing equal bond types when one is sigma and one is pi; say out loud that the in-plane sp two bonds are sigma and the perpendicular p gives the pi overlap so you keep the distinction. A third confusion is mixing up angles; repeat that the in-plane angles are one hundred twenty degrees and the perpendicular p is at ninety degrees to the plane to lock in the numbers.

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    sp2 Geometry: 120° Plane and Perpendicular p

    1. Visualize sp2 carbon as flat
    2. Draw three orbitals at 120°
    3. Imagine a perpendicular p orbital
    4. Use tabletop and pencil analogy
    5. Remember sigma bonds lie in plane
    6. Pi bonds form from side overlap

    sp2 Orbital Angles and Perpendicular p

    1. Thinking orbitals just point to electrons
    2. Confusing sigma and pi bond types
    3. Mixing up 120° and 90° angles

    sp2, sp2geometry, orbitals, moleculargeometry, pibond, sigmabond, hybridization, organicchemistry, carbon, orbitalangles

  • How are sp2 orbitals formed from carbon’s valence orbitals?

    sp two orbitals form when the two s orbital mixes with two of the three two p orbitals, producing three equivalent sp two hybrids and leaving one unhybridized two p orbital.

    Think of the carbon atom like a tiny set of building blocks that make bonds. Carbon has one two s block and three two p blocks in its outer shell, and when it needs three evenly spaced bonds it blends the two s block with two of the two p blocks to make three new identical sp two blocks. Those three sp two blocks point out in a flat triangular shape, each able to form a strong single bond, while the leftover two p block stands straight up and can form a sideways overlap called a pi bond. This mixing of orbitals is called hybridization and it helps explain the geometry and bonding we see in molecules like ethene.

    A common mistake is thinking all the two p blocks get used in hybridization so that there are no leftover orbitals, which would make pi bonds impossible; remember one two p stays unhybridized and makes the pi bond. Another mistake is picturing the hybrids as physical blobs mixing like paint rather than quantum orbital shapes; it is better to think of them as mathematical combinations that change where electron density is most likely to be. Some students also confuse the number of hybrids with the number of electrons, so keep in mind the count comes from how many orbitals mix, not how many electrons occupy them.

    For more videos and resources on hybridization and other chemistry topics visit w w w dot gumball degree dot com.

    sp2 Hybridization in Carbon

    1. Blend 2s with two 2p orbitals
    2. Form three equivalent sp2 hybrids
    3. Arrange hybrids in flat triangular shape
    4. One 2p remains unhybridized
    5. Unhybridized 2p forms a pi bond

    Common sp2 Hybridization Mistakes

    1. Assuming all 3 two p orbitals hybridize
    2. Thinking hybrids are physical paint mixing
    3. Confusing number of hybrids with electrons

    sp2, hybridization, carbon, valencebondtheory, moleculargeometry, piBond, ethene, orbitalmixing, chemistry, bonding

  • Difference between single, double, and triple bonds?

    A single bond shares one electron pair as in methane, a double bond shares two electron pairs as in ethylene, and a triple bond shares three electron pairs as in acetylene.

    Think of atoms as friends holding hands to stay together: a single bond is one pair of hands held between two atoms so they are connected but can still rotate around each other; a double bond is like two pairs of hands, which makes the connection stronger and prevents easy rotation so the atoms stay in a flatter arrangement; a triple bond is three pairs of hands, which makes the connection very strong and very short, keeping the atoms tightly aligned. In hydrocarbons the atoms involved are carbon and hydrogen or carbon and carbon, and the examples show how carbons link differently: methane has carbons linked with single bonds to hydrogens, ethylene has a carbon to carbon double bond, and acetylene has a carbon to carbon triple bond.

    Students often think more bonds always mean more atoms, but it actually means more shared electron pairs between the same two atoms, so check whether the bond is between the same atoms. Another common mistake is imagining double and triple bonds as simply thicker lines without recognizing they restrict rotation, so remember double and triple bonds lock the shape more than single bonds. Some learners confuse examples and might name a nonhydrocarbon for these bonds, so always pick hydrocarbon examples like methane, ethylene, and acetylene.

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    Types of Bonds in Hydrocarbons

    1. Atoms hold hands to bond
    2. Single bond allows rotation
    3. Double bond restricts rotation
    4. Double bond creates flatter shape
    5. Triple bond is very strong
    6. Triple bond keeps atoms aligned

    Common Bonding Mistakes in Hydrocarbons

    1. Thinking more bonds means more atoms
    2. Viewing multiple bonds as thicker lines
    3. Confusing hydrocarbons with nonhydrocarbons

    hydrocarbons, chemicalbonds, singlebond, doublebond, triplebond, bonding, organicchemistry, molecules, carbonbonds, chemistrybasics

  • What symmetry elements are in staggered ethane?

    Staggered ethane has D three d symmetry, with a principal C three rotation axis along the carbon-carbon bond, three C two axes perpendicular to it, a center of inversion, and three reflection operations that can be described as improper rotations or vertical planes depending on the description.

    Think of ethane as two marshmallows (the carbon atoms) joined by a stick, with three little candies (the hydrogen atoms) arranged in a triangle around each marshmallow, and the triangles are rotated so the candies are not lined up; that rotated arrangement is called staggered and gives the molecule special symmetry. The main symmetry is a threefold rotation along the stick, which means you can turn the molecule by one third of a full turn and it looks the same, and there are three twofold rotations that flip the molecule across axes perpendicular to the stick so pairs of hydrogens swap places. There is also a point right in the middle where every atom reflects through to an opposite partner called an inversion center, and some descriptions count certain mirror-like operations that combine rotation and reflection.

    Students often think staggered ethane lacks any mirror symmetry because they only look for simple flat planes, but the molecule does have symmetry operations that act like mirrors when combined with rotation, so remember to consider improper rotations and inversion as valid symmetry elements. Another common mistake is counting the three twofold axes as coincident with the principal axis; they are actually perpendicular to it, so picture them crossing the stick at right angles to avoid confusion. A final error is assuming the eclipsed form has the same symmetry; it does not, because alignment of hydrogens in eclipsed ethane reduces the number and type of symmetry elements compared to the staggered form.

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    Staggered Ethane Symmetry Elements

    1. Visualize ethane as two carbons
    2. Hydrogens form triangular arrangements
    3. Triangles are rotated in staggered form
    4. Threefold rotation around C–C bond
    5. Three twofold perpendicular rotations
    6. Inversion center at molecule midpoint

    Common Mistakes in Ethane Symmetry

    1. Ignoring improper rotations and inversion
    2. Misplacing C2 axes relative to C3 axis
    3. Confusing eclipsed and staggered symmetry

    ethane, molecularsymmetry, D3d, staggered, C3axis, C2axes, inversioncenter, chemistrytutorial, organicchemistry, symmetryelements

  • Polarity of C–H bonds in ethane?

    C–H bonds in ethane are essentially nonpolar to only slightly polar because carbon and hydrogen have similar electronegativities, so the electrons are shared relatively evenly.

    Think of a C–H bond like two children holding a jump rope—if both children pull about the same, the rope stays in the middle; that is what happens with electrons when carbon and hydrogen bond because their electronegativities are close. Molecular orbital overlap means the atomic orbitals of carbon and hydrogen merge to form a shared space where electrons live, and because the orbitals overlap well and the atoms have similar pull on electrons, the shared electrons spend nearly equal time around each atom. This makes each bond have almost no charge separation, so ethane as a whole is nonpolar. If you imagine tiny partial charges, they are very small and do not make the molecule behave like a polar substance.

    Students often think any bond to carbon is always nonpolar, but if carbon bonds to much more electronegative atoms like oxygen or nitrogen, those bonds become noticeably polar, so always compare electronegativities. Another common mistake is picturing molecular orbitals as separate blobs instead of shared regions; remember they are regions where electrons are likely to be found, formed by the combination of atomic orbitals. Some learners assume small polarity means no effect at all, yet slight polarities can influence reaction pathways and intermolecular interactions, so note the context when deciding if the polarity is important.

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    C–H Bond Polarity in Ethane

    1. Electrons shared relatively evenly
    2. Orbitals merge to form shared space
    3. Good orbital overlap reduces polarity
    4. Similar electronegativities minimize charge separation
    5. Small partial charges are negligible

    Common Mistakes in C–H Bond Polarity

    1. Assuming all carbon bonds are nonpolar
    2. Misvisualizing molecular orbitals as separate blobs
    3. Ignoring small polarities’ chemical effects

    CH_bond,C_H_polarity,ethane,molecular_orbitals,electronegativity,orbital_overlap,organic_chemistry,bond_polarity,chemical_bonding,partial_charges

  • Why do alkanes release so much energy when burned?

    Alkanes are good fuels because burning them converts many relatively strong carbon hydrogen and carbon carbon bonds into even stronger carbon oxygen double bonds in carbon dioxide and oxygen hydrogen single bonds in water, and that net formation of stronger bonds releases a large amount of energy.

    Think of a molecule of ethane like a short chain made of carbon links with lots of hydrogen beads attached; each carbon hydrogen and carbon carbon bond holds energy, and when oxygen comes in during combustion those bonds break and new bonds form that are lower in energy and much more stable. Breaking bonds costs some energy but making the new carbon oxygen double bonds in carbon dioxide and oxygen hydrogen bonds in water gives back more energy than was used, so there is leftover energy released as heat. Because ethane and other alkanes have many carbon hydrogen and carbon carbon bonds available to convert into those very stable products, the total energy released is large, which is why they make good fuels. You can picture it like replacing medium strength springs with very tight springs and getting extra snap energy out of the change.

    A common mistake is thinking that stronger bonds always give more energy when formed; what matters is the difference between bonds broken and bonds formed, so focus on net energy change rather than individual bond strengths. Another misconception is that carbon carbon bonds are unimportant; while carbon hydrogen bonds often dominate the energy picture, carbon carbon bonds contribute substantially in larger alkanes and increase the total energy released per molecule. A practical tip is to compare typical bond energy numbers qualitatively: carbon oxygen double bonds and oxygen hydrogen bonds are notably stronger than carbon hydrogen and carbon carbon bonds, so their formation drives the large heat release.

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    Why alkanes release energy when burned

    1. Ethane is a chain of carbons and hydrogens
    2. Bonds break and new bonds form
    3. Forming CO2 and H2O bonds releases energy
    4. Breaking bonds costs energy first
    5. Net energy release equals energy out

    Common mistakes about bond energy

    1. Thinking stronger bonds always give energy
    2. Ignoring C–C bond contributions
    3. Focusing on individual bonds not net

    alkanes, combustion, bondenergy, chemistry, fuel, ethane, carbonhydrogen, carboncarbon, energyrelease, chemistryeducation