Single vs. Double bonds

[VLi_2B]

Why are single bonds longer than double bonds?

[Alex Tchekanov Dis 2k]

When there is a double bond, there are more electrons being shared between the two atoms, thus the attraction between the nucleus of the atoms (the positively charged regions) are pulling on two negatively charged electrons instead of one. This is a stronger attraction than a single bond with one electron being attractive to the nucleus. That is also why a triple bond is shorter than a double bond.

[Matthew Tsai 2H]

Because there are more electrons being shared between the atoms, there is a greater attractive force that pulls the atoms closer together, shortening bond length.

[Qilan Li 4I]

In double bonds, there are four bonding electrons between two atoms instead of two in single bonds so there is more attraction between the atoms when there is a double bond. Stronger Attraction = Shorter Bond

[Jessica Tejero 3L]

Double bonds involving carbon are stronger than single bonds and are also shorter. Double and triple covalent bonds are stronger than single covalent bonds.

[Donavin Collins 1F]

Since the double bond creates a stronger bond, the attraction pulls the atoms closer together which shortens the length of the bond.

[Sydney Pell 2E]

Sometimes, if the structure has resonance, the double bond may not be much longer than the single bond. This occurs only if a species is resonant because all of its possible resonant structures blend, thus creating a partial double bond structure and making the double bond shorter than it otherwise would have been, but still longer than the normal single bond.

[Samuel Tzeng 1B]

Since double bonds are stronger, they pull the atoms closer together and are therefore shorter.

[Veronica Lu 2H]

The double bonds are much stronger than single bonds, therefore the pull is stronger making them shorter

[Aadil Rehan 1D]

Fun fact: the shorter double bonds means that the stereochemistry (shape chemistry) is also greatly simplified.

[zachary_nhem_4I]

More electrons leads to shorter bonds while less electrons means less of an attraction

[RichBollini4G]

Why are single bonds longer than double bonds?

The attraction is stronger in the double bond, since there are more electrons, which pulls the atoms closer together, causing the bond length to be shorter than a single bond.

[Kelsey Ash 1D]

Double bonds are stronger and pull the atoms closer together which makes them shorter

[nicole-2B]

There are more electrons being shared so there is a greater attraction causing for shorter bonds.

[ranqiao1e]

Because the strength of the single bond is much weaker than double bonds, so the electrons are held less closely together.

[305416361]

Single bonds are a lot weaker than double bonds because there are less electrons involved in the bonding process. Since they are weaker, they aren't pulled as closely together, whereas double bonds are stronger and pulled closer to each other, and triple bonds even stronger and closer than that