An Element Has Z=38 and 50 Neutrons, What Element and Isotope

Multiple Choice

An element has Z=38 and 50 neutrons, what element and isotope is it?

A) ${ }_{38}^{50} \mathrm{Sr}$
B) ${ }_{38}^{88} \mathrm{Sr}$
C) ${ }_{50}^{38} \mathrm{Sr}$
D) ${ }_{50}^{88} \mathrm{Sr}$