The total numbers of neutrons, protons, and electrons in 35Cl- are ________.
A) 17 neutrons, 35 protons, 36 electrons
B) 35 neutrons, 17 protons, 18 electrons
C) 18 neutrons, 17 protons, 16 electrons
D) 18 neutrons, 17 protons, 18 electrons
E) 17 neutrons, 17 protons, 17 electrons

Question

Quizplus · Accepted Answer

The atomic number (number of protons) of chlorine is 17. The negative charge of the ion tells us that there is one more electron than the number of protons, making it 18 electrons. To find the number of neutrons, we subtract the atomic number from the mass number (rounded atomic mass). The mass number of 35Cl is 35, so we subtract 17 from 35 to get 18 neutrons. Therefore, the total numbers of neutrons, protons, and electrons in 35Cl- are 18 neutrons, 17 protons, and 18 electrons (choice D).

The Total Numbers of Neutrons, Protons, and Electrons in 35Cl-