Orbital Structure Of Methane
When sp3 orbitals are formed, they arrange themselves so that they are as far apart as possible.
That is a tetrahedral arrangement, with an angle of 109.5°.
The ‘s’ and ‘p’ orbitals of carbon hybridize to form four identical sp3 hybrid orbitals with hydrogen atoms.
It is easy to see that the the four hydrogen atoms that will bond with the carbon all have a single 1s orbital with a single unpaired electron in each. This makes it very easy for it to bond with the carbon.
At this point, it is important that we notice how the 1s orbital of each of the four hydrogen comes together with the sp3 orbital of the central carbon. The two types of orbital's overlap in an end to end manner and form four single bonds which are referred to as sigma bonds giving us our methane molecule.
Example: Methane.
sp3 hybridization in Methane