Which scientist saw the atom as a positively charged sphere with negative particles ( electrons ) embedded within?

Thomson discovered the first subatomic particle, the electron, while researching cathode rays. To explain the neutrality of atoms, Thomson proposed a model of the atom in which negative electrons are scattered throughout a sphere of positive charge. He called his atom the plum pudding model.

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it