We call these reactive elements, becausethese atoms really like to follow the buddysystem and form bonds with other atoms.Noble gases, however, don't have thisproblem. Their outer shells are filled to the max, so they don't need to bond or react with any other atoms.
The greenhouse effect is when Earth's atmosphere gets surrounded with gasses causing the Earth to warm up.
I think its A because some scientist from the Department of Physics of Northeastern University found out that is not a part of Dalton's atomic theory.
