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The atomic number of Re is 75. The atomic mass of one of its isotopes is 186. How many neutrons are in an atom of this isotope?

A. 75
B.111
C. 186
D. 261

User Bnil
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2 Answers

4 votes

Answer:111

Step-by-step explanation:

User Alonme
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4 votes

Answer:

B.111

Step-by-step explanation:

Atomic mass = number of protons(or atomic number) + number of neutrons

186 = 75 + number of neutrons

number of neutrons = 186 -75 = 111

User Chris Van Opstal
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