Which of the following three drawings represents a neutral Na atom? (a) (b) (c)

Video transcript

Hey everyone in this example, we need to determine the number of each subatomic particle in our given chemical symbol of our unknown element. So analyzing this chemical symbol, we recognize that we have the number 20. In the left hand subscript of our chemical symbol. And we want to recall that the left hand subscript gives us our atomic number of our given element. And so we want to recall that the atomic number is described by the number of protons, which is equal to the number of electrons according to our given atom. And so this would actually allow us to so far rule out A B C. As well as E. Because option D. Is the only choice where the number of protons is equal to our number of electrons. And so let's continue to further understand the second number within our chemical symbol, which is that number 42. And the left hand superscript of our chemical symbol. So we want to recall that 42 it described as the mass number of our chemical symbol or are given element. And we want to recall that the mass number is described as our number of our protons added to our number of neutrons. And we would next recall that our number of neutrons are found from our mass number minus our atomic number. And so we would essentially find that our number of neutrons for this given element is equal to r given mass number, which we know is equal to 42 because it's in the left hand superscript. And we subtract this from our atomic number being 20, which would give us a number of neutrons equal to a value of 22. And so answer choice D definitely makes sense as a correct choice because everything corresponds with the number of protons equaling the number of electrons and our number of neutrons equaling 22 from our calculations. So this completes this example as our final answer, We've determined the value of each of the subatomic particles, so if you have any questions, please leave them down below and I will see everyone in the next practice video.