How would a variety of organic compounds be different if carbon had seven electrons in its outermost energy level instead of four

The variety would be less, this is because if carbon had seven electrons then it wouldn't be able to bond with as many different atoms at the same time.

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.