1) an atom consists of positive charge and electrons are embedded in it.
2) positive and negative charge are equal in magnitude. so atom is whole neutral
Thomson introduced first model of atom i.e. thomson model of atom. He said that atom of an element consists of positive charge and electrons (negative charge) embedded in it.he compared that we the Christmas pudding in which cristmas pudding was the positive sphere and its currants were electrons it could also be compared To a watermelon , taking red flesst part as positive charge sphere and it's black seeds as electrons . This was just the Thomson model.