Ca-40,K-39,and Sc-41 all have the same
A)atomic mass.
B)atomic number.
C)number of electrons.
D)number of neutrons.

Question

Quizplus · Accepted Answer

Ca-40, K-39, and Sc-41 all have different atomic numbers, so they cannot have the same number of electrons. However, they do all have 20 neutrons, which is the same number of neutrons as Ca-40 and Sc-41 have protons (their atomic numbers). This means that K-39 has one fewer neutron than protons, giving it a slightly different mass (39 instead of 40 or 41). Therefore, the only option that they could have in common is the number of neutrons, which is D.

Ca-40,K-39,and Sc-41 All Have the Same