Answer:
Hey,
All the answers should be blue.
<em>Edg 2020/2021</em>
Answer:
it is an 3d array of structure which involves inopperation methods
Explanation:
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The formular for determinatio of mass number is this:
Mass number = number of proton + number of neutron
From the question, we are told that:
Mass number = 39
Proton number = 19
Number of proton = ?
Number of neutron = mass number - number of proton
Number of neutron= 39 - 19 = 20
Therefore, number of neurtron = 20.