Tritium is an isotope of hydrogen with a mass number of 3. Which of the following accurately represents tritium?
A) ${ } _ { 1 } ^ { 1 } \mathrm { H }$
B) ${ } _ { 1 } ^ { 2 } \mathrm { H }$
C) ${ } _ { 1 } ^ { 3 } \mathrm { H }$
D) ${ } _ { 2 } ^ { 1 } \mathrm { H }$
E) ${ } _ { 3 } ^ { 1 } \mathrm { H }$

Question

Quizplus · Accepted Answer

The mass number of an element or isotope is equal to the sum of the number of protons and neutrons in the nucleus. Tritium has a mass number of 3, so it must have one proton (since it is hydrogen) and two neutrons. The symbol for tritium is ${ } _ { 1 } ^ { 3 } \mathrm { H }$, as it has one proton and three nucleons in total (one proton and two neutrons).

Tritium Is an Isotope of Hydrogen with a Mass Number 11H{ } _ { 1 } ^ { 1 } \mathrm { H }11​H

Tritium Is an Isotope of Hydrogen with a Mass Number ${ } _ { 1 } ^ { 1 } \mathrm { H }$