Where is most of mass in the plum pudding model?

In the plum pudding model, most of the mass is thought to be concentrated in a diffuse, positively charged "pudding" that fills the atom. This pudding is interspersed with negatively charged electrons, resembling plums within the pudding. The model, proposed by J.J. Thomson in the early 20th century, suggests that the mass of the atom is primarily due to this positive charge, with the electrons contributing to the overall structure rather than mass. However, this model has since been replaced by the more accurate nuclear model of the atom.