Case Western Reserve University

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Problem 17

Challenge An atom has a mass number of 55. Its number of neutrons is the sum of its

atomic number and five. How many protons, neutrons, and electrons does this atom have?

What is the identity of this atom?

Answer

The protons' number $=25,$ the neutrons' number is $30,$ electron number $=25,$ this

element is manganese.

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## Discussion

## Video Transcript

this question is really just a math problem. So we know that the formula is made up of the number of per tons and the number of nutrients. Because electrons don't have a little mass, they don't contribute. Therefore, our equation is just Brotons plus pro council is five to make it in Brittany Trance, which 55. So we subtract five from both sides. Divide by two when we get 25. So we have 25 bro towns, which is 25 electrons, 30 neutrons. So if we look up using a gob, the people will see that we have Magnin ese.

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