How many protons are in an isotope of sodium with a mass number of 25?
A)11
B)14
C)15
D)25
E)32

Name: How many protons are in an isotope of sodium with a mass number of 25? A)11 B)14 C)15 D)25 E)32
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Quizplus · Accepted Answer

The atomic number of sodium is 11, which tells us that a neutral sodium atom has 11 protons. The mass number of the isotope is 25, which is the sum of the number of protons and neutrons in the nucleus. Therefore, the number of neutrons in this isotope is 25 - 11 = 14.

How Many Protons Are in an Isotope of Sodium with a Mass