The atoms of a particular element all have the same number of protons as neutrons.Which of the following must be true?
A)The atomic weight must be a whole number.
B)The mass number for each atom must equal the atomic weight of the element.
C)The mass number must be exactly twice the atomic number for each atom.
D)All of these are true.

Question

Quizplus · Accepted Answer

The mass number is the sum of protons and neutrons in an atom's nucleus. If an element's atoms have the same number of protons and neutrons, then the mass number (protons + neutrons) would indeed be twice the atomic number (number of protons). Choices A and B are not necessarily true because the atomic weight of an element can be a decimal due to the presence of isotopes, and the atomic weight is an average that may not match the mass number of any specific atom.

The Atoms of a Particular Element All Have the Same