Question

Consider the era of atoms, and the “before and after”. If the “after box” had eight H atoms, two He atoms, one Li atom and one Be atom, how many particles were in the “before box”? How many of each kind of particle? Justify your answer.

Answer 1

since each different atoms are differ only about their number of electron and nucleons. here in this case atoms are distinguishable or in the era of after atom the box contains specifically 8 H atoms , 2 He atoms , 1 Li atoms and 1 Be atom . if one could observe before the era of atoms he could finds 12 atoms or particles with same kind. because before atom defines the all material are considered as made up of single entitity. and all particles were same in that era. it is difficult or not much knowledge to identify each unique particles in that era.