A neutral atom is represented as 1531X. Which statement is correct?
It has 15 protons, 16 neutrons, and 15 electrons.
It has 16 protons, 15 neutrons, and 15 electrons.
It has 15 protons, 31 neutrons, and 16 electrons.
It has 31 protons, 15 neutrons, and 31 electrons.