The volume measuring system for a gasoline pump at the service station is calibrated at 20.0°C. If the temperature of the gasoline drops to 10.0°C, what percentage extra amount of mass of gasoline do you receive when making a purchase? The coefficient of volume expansion for gasoline is 9.5 × 10-4/K.

Methane CH4 is molecule with 4 C-H bonds and adopts a tetrahedral geometry.

Now, The valence electron configuration of C = 2s²2p²

H = 1s¹

The electrons are paired in the 2s orbital whereas there exits 2 unpaired electrons in the 2p-orbital.

In order to form four bonds with the 4 H atoms in CH4, we need 4 unpaired electrons. These are created when an electron from the 2s orbital gets promoted to the 2p orbital. This results in the mixing of the 2s and 2p ( three 2p orbitals) forming 4-sp3 hybrid orbitals on the C atom. Each of the four hybrid orbitals then go on to form a sigma bond with each of the four 1s orbital of the H atom.

Ans: (d) The carbon atom promotes one electron from the s orbital into the p orbital, which creates four half-filled orbitals available to accept one electron from four different hydrogen atoms.