Multiple Choice
Given that the mass of the isotope Br-81 is 80.9163 amu, which statement is correct about Br-81?
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Isotopes
Multiple Choice
An isotope of yttrium has 39 protons and 59 neutrons. What is the mass number of this isotope?
A
39
B
98
C
20
D
59
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Verified step by step guidance1
Recall that the mass number of an isotope is the total number of protons and neutrons in its nucleus.
Identify the number of protons given in the problem, which is 39 for this yttrium isotope.
Identify the number of neutrons given in the problem, which is 59 for this isotope.
Use the formula for mass number: \(\text{Mass Number} = \text{Number of Protons} + \text{Number of Neutrons}\).
Add the values: \$39 + 59$ to find the mass number of the isotope.
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