Why does a molecule of methane have 10 electrons?
I used to think that the number of electrons in methane were 8 in number but it turns out that there are 10 in number but i dont know why. Please help Regards
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Methane, CH₄ has an atom of C and 4 atoms of H.
Looking at the structure of CH₄, there are 4 sigma bonds present. A sigma bond is a type of covalent bond. Each covalent bond represents a pair of electrons shared between two atoms.
This gives us 8 electrons; however one must realize that there is a pair of electrons from 1s² orbital (of the Carbon atom) which is not participating in any form of bonding. Hence the total 10 electrons present in a molecule of CH₄.
Another simple way to know the total number of electrons is to know the atomic numbers of the individual atoms (6 for carbon, and 1 for each hydrogen), so 6 + 1*4 = 10 electrons. Now check the formal charge present on the molecule (in this case it is 0, CH₄ is electrically neutral - if a positive charge 'x' is found, subtract 'x' from 10 & if a negative charge 'y' is found, add 'y' to 10. Again, a total of 10 electrons is found.