Multiple Choice
How many neutrons are in the nucleus of a potassium atom with a mass number of 39?
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- 1. Intro to General Chemistry3h 48m
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2. Atoms & Elements
Isotopes
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
An atom's mass number is 13 and its atomic number is 6. How many neutrons are in its nucleus?
A
6
B
19
C
7
D
13
Verified step by step guidance1
Identify the given values: the mass number (A) is 13 and the atomic number (Z) is 6.
Recall that the atomic number (Z) represents the number of protons in the nucleus of an atom.
Understand that the mass number (A) is the sum of protons and neutrons in the nucleus.
Use the formula to find the number of neutrons: Neutrons = Mass Number - Atomic Number.
Substitute the given values into the formula: Neutrons = 13 - 6.
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