The instability of uranium-235 compared to uranium-238, along with the relative stability of hydrogen compared to tritium, shows that the stability of a given nucleus depends upon
A) the speed of electrons orbiting the nucleus: more mass means more gravitational pull.
B) adding or subtracting neutrons, which can change a stable isotope into an unstable isotope.
C) the mass: heavier nuclei are always less stable.
D) the number of electrons in the nucleus.

Question

Quizplus · Accepted Answer

The addition or subtraction of neutrons can change a stable isotope into an unstable isotope. This is evident in the instability of uranium-235 compared to uranium-238, which differ in the number of neutrons they possess. Similarly, the relative stability of hydrogen compared to tritium is due to the fact that hydrogen possesses one proton and no neutrons, while tritium possesses one proton and two neutrons. The additional neutron destabilizes the nucleus, making it less stable than hydrogen. The speed of electrons orbiting the nucleus (choice A), mass (choice C), and the number of electrons in the nucleus (choice D) do not directly impact the stability of the nucleus.

The Instability of Uranium-235 Compared to Uranium-238, Along with the Relative