Atom
An atom has nucleus (containing Proton and Proton and Neutron) with surrounding electron cloud.
They have negative mass?? https://www.voanews.com/a/influentual-physicist-albert-einstein-is-born-in-1879-this-day-in-history/3764911.html
An atom has nucleus (containing Proton and Proton and Neutron) with surrounding electron cloud.
They have negative mass?? https://www.voanews.com/a/influentual-physicist-albert-einstein-is-born-in-1879-this-day-in-history/3764911.html