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03-06-2018
Physics

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How many neutrons does element X have if its atomic number is 31 and its mass number is 90?

Respuesta :

Porshia Porshia

03-06-2018

Things you need to know:
Atomic number= protons,
Protons + neutrons= mass number.
This means 31 + x = 90
Subtract 31 from both sides and you get x= 59
Answer is 59 neutrons

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