Final answer:
In the plum pudding model, the positive charge is spread throughout the atom in a jelly-like or muffin substance, with the electrons embedded within it like plums in a pudding or blueberries in a muffin.
Step-by-step explanation:
In the plum pudding model, the positive charge of the atom is distributed throughout the entire sphere of the atom, much like a diffused cloud or jelly. This model was proposed by J.J. Thomson following his discovery of the electron. He compared the atom to a plum pudding or a blueberry muffin, where the positive charge represents the pudding or muffin itself, and the electrons are like the plums or blueberries embedded within it. Hence, the electrons were believed to be set in a uniform sphere of positive charge, with the possibility of being somewhat mobile within this positively charged sphere.