Answer: The correct statement is the positive charge in an atom must be located in a dense central mass.
Step-by-step explanation:
Rutherford gave an experiment called as gold foil experiment.
In his experiment, he took a gold foil and bombarded it with alpha particles which carry positive charge of +2 units. He at first thought that the particles will pass straight through the foil, but to his surprise, many of them passed through, some of them deflected their path and a few of them bounced back straight from their path.
From this observations, he concluded that in an atom, there exist a small positive charge that is present at the center. Because of this positive charge, the alpha particles deflected their path and some of them bounced straight back their path.
Thus, the correct statement is the positive charge in an atom must be located in a dense central mass.