Which statement is not true?

all planets revolve around the sun.
some planets revolve backwards.
all planetary orbits are elliptical.
all planets spin/rotate on their axis.

All planets revolve around the sun. - Incorrect. There are many planets that revolve around other stars.

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.