I was taught in high school that carbon atoms by themselves are capable of establishing covalent bonds with with as far as four hydrogens atoms.

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Nowadays, trying to understand the topic in-depth, I am confused about orbitals regarding this case. As far as I know, in the carbon atom's outer shell, the 2s orbital is filled, and the 2p orbital has two lonely electrons, but at the same time, each hydrogen forms a bond with one of this outer shell electrons. Does this mean the 2s orbital splits, or is there any other explanation?