Draw the Lewis dot structure for each atom of the compound to show how many valence electrons are present in each atom. For example, the calcium atom in calcium chloride, CaCl2, has two valence electrons, and the chlorine atoms have seven valence electrons each.
The correct is this because they said
Atomic number of C is 6. Hence, there are 6 electrons in carbon.
The electronic configuration of carbon is 1s2, 2s2, 2p2
Here, there are 2 unpaired electron. However, C2+ ions have 2 electrons less as compared to C.
Hence, electronic configuration of C 2+ ion is 1s2, 2s2. All the electrons are paired in this system. So there are no unpaired electrons in C 2+ ion.
When organisms and plants died and sank to the bottom of swamps and oceans, brown soil-like materials called peat are formed. Over millions of years, the peat became covered with sand, clay and other minerals and the peat is converted into layers of sedimentary rocks. After a long time, different type of fossil fuels are formed.