My teacher says in picture (1) carbon atom is Asymmetric carbon atom. I don't know why. I know asymmetric carbon atom are those carbon atoms which are bonded with four different groups/atoms by single bonds. But why would we treat a negative sign as a group or atom? And I also want to ask for whatever reason we are treating negative sign as a different group we must treat + sign in a same way. Hence, carbon atom in (2) should also be asymmetrical. Right?