If someone tells you they have a sample of niobium-90,can you tell how many neutrons are in the nucleus?
A)Yes,there are 41 neutrons.
B)Yes,there are 90 neutrons.
C)Yes,there are 49 neutrons.
D)No,more information must be given.
E)No,there is no such thing as "niobium."

Question

Quizplus · Accepted Answer

Niobium-90 has an atomic number of 41, which means it has 41 protons. The number of neutrons is the mass number (90) minus the number of protons (41), which equals 49 neutrons.

If Someone Tells You They Have a Sample of Niobium-90,can