Which of the following gives the correct numbers of protons, neutrons, and electrons, respectively, in a neutral atom of 11850 Sn?
A)68 protons, 68 neutrons, 50 electrons
B)118 protons, 50 neutrons, 118 electrons
C)118 protons, 118 neutrons, 50 electrons
D)50 protons, 50 neutrons, 50 electrons
E)50 protons, 68 neutrons, 50 electrons

Question

Quizplus · Accepted Answer

The atomic number of tin (Sn) is 50, which means it has 50 protons and 50 electrons in a neutral atom. The mass number of 11850 Sn tells us that the total number of protons and neutrons is 118. Thus, subtracting the atomic number from the mass number gives the number of neutrons:

Number of neutrons = mass number - atomic number
Number of neutrons = 118 - 50
Number of neutrons = 68

Therefore, a neutral atom of 11850 Sn has 50 protons, 68 neutrons, and 50 electrons, and the best choice is E.

Which of the Following Gives the Correct Numbers of Protons