<s>[INST] In a methane molecule what is the valence of the carbon atom? [/INST] In a methane molecule (CH4), the carbon atom has a valence of four. This means that the carbon atom has four electrons in its outermost energy level or valence shell, which is the maximum number of electrons that this shell can hold. In methane, each of the four valence electrons of the carbon atom is shared with one of the four hydrogen atoms, resulting in a stable molecule.</s>\ <s>[INST] If methane is a stable molecule then why is it bad for the ozone layer and environment? [/INST] Methane does not affect the ozone layer in the stratosphere. Rather, methane decomposes into ozone when exposed to sunlight, and ozone is a pollutant that damages the respiratory system of human beings at near ground level.

Methane is also a much more potent greenhouse gas than carbon dioxide and contributes significantly to global warming.</s>