If a negative 1 ion has 10 electrons what element is it

To be neutral, an atom has to have an equal number of protons (+1 charge) as electrons (-1 charge) . So if our 'mystery' element has 10 electrons, it must also have 10 protons. The number of protons in an atom is given by its Atomic Number in the periodic table. The element with an atomic number of 10 is Neon (Ne).

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.