In a ${ } _ { 56 } ^ { 135 } \mathrm { Ba }$ nucleus, the numbers of protons, neutrons, and electrons are
A) 56, 79, and 135, respectively.
B) 56, 79, and 0, respectively.
C) 79, 56, and 135, respectively.
D) 79, 56, and 0, respectively.
E) None of the previous answers is correct.

Question

Quizplus · Accepted Answer

The atomic number (56) indicates the number of protons, and the mass number (135) minus the atomic number gives the number of neutrons (79). In a nucleus, there are no electrons.

In A 56135Ba{ } _ { 56 } ^ { 135 } \mathrm { Ba }56135​Ba

In A ${ } _ { 56 } ^ { 135 } \mathrm { Ba }$