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An atom of a mystery element contains 7 protons, 7 neutrons, and 7 electrons.

What is the mass number?
A. 14
B. 7
C. 0
D. 21

User SenorAmor
by
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1 Answer

2 votes

A-14

Step-by-step explanation:

Mass number (MN) = Proton number + Neutron number

MN=7+7

MN=14

User Jonathon Reinhart
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