Why does Methane lack 90 degree angles?

In summary: Thanks.In summary, the tetrahedral structure of methane is due to its symmetry. The carbon hydrogen bonds are sp3 hybrid bonds, which results in a tetrahedron.
  • #1
Physt
49
1
With the Methane structure of CH4 and an electron structure of Carbon as 1s22s22px12py1 and the electron structure of Hydrogen as 1s1 with P-orbitals separated by 90 degrees from each other and S-orbitals uniform spheres why aren't two of the Hydrogen atoms in a Methane molecule at 90 degree angles (or at some balance between there and the homogenous 109.5 degree angles shown between all Hydrogen atoms)?
 
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  • #2
Methane has a tetrahedral structure due to its symmetry. The carbon hydrogen bonds are SP3 hybrid bonds. http://en.wikipedia.org/wiki/Orbital_hybridisation#sp3_hybrids
There are no unbonded electron pairs on the carbon, so the bonds should distribute themselves more or less equally spaced, which gives a tetrahedron.
 
  • #3
Khashishi said:
Methane has a tetrahedral structure due to its symmetry. The carbon hydrogen bonds are SP3 hybrid bonds. http://en.wikipedia.org/wiki/Orbital_hybridisation#sp3_hybrids
There are no unbonded electron pairs on the carbon, so the bonds should distribute themselves more or less equally spaced, which gives a tetrahedron.
Right, but if three of the bonds are hybrid bonds why are they not spaced 90 degrees from each other (or more towards 90 degrees than the even 109.5 degrees all around) with the remaining 2s bond spaced evenly away from each of them? Are the 2p shells just a rough "the bond must be within this region" and if so are the Hydrogen atoms spaced at different distances away from the Carbon atom? What I'm trying to understand is why there appears to be no relation between the orbital theory (beyond the total number of possible bonds irrespective of the angles of the bonds) and the location of atoms with regard to each other.
 
  • #4
Physt said:
Right, but if three of the bonds are hybrid bonds

All four are. sp3 means mixing four bonds (one s and three p) into another four.
 
  • #5
Borek said:
All four are. sp3 means mixing four bonds (one s and three p) into another four.
Thanks. Likewise for your post in the other thread.
 

Related to Why does Methane lack 90 degree angles?

1. Why does methane have a tetrahedral shape?

Methane has a tetrahedral shape because it follows the VSEPR theory, which states that molecules will adjust their shape to minimize repulsion between electron pairs.

2. How does the electron configuration of methane affect its shape?

The electron configuration of methane, with four bonding pairs and no lone pairs, results in a symmetrical tetrahedral shape to minimize electron repulsion.

3. What causes the 109.5 degree bond angle in methane?

The 109.5 degree bond angle in methane is due to the tetrahedral arrangement of the four bonding pairs, resulting in the optimal angle for minimizing repulsion between pairs.

4. Is methane's shape affected by the size of the atoms?

Yes, the size of the atoms in methane does affect its shape. Larger atoms will result in slightly larger bond angles due to increased electron repulsion.

5. Can methane ever have a 90 degree angle?

No, methane cannot have a 90 degree angle due to the tetrahedral arrangement and the repulsion between electron pairs. However, in certain cases, the bond angle may deviate slightly from 109.5 degrees due to the presence of other atoms or molecules nearby.

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