How many protons and neutrons are in the nucleus of the following atoms? (a)

Video transcript

Hey everyone in this example, we need to figure out how many neutrons and protons are in our isotope of platini um we want to recall that in our isotope symbol. We have X representing our isotope adam we have a in the left hand superscript representing our mass number. Which we can find by taking our number of protons and adding that to our number of neutrons. And then Z is in the left hand subscript, which we recall represents our atomic number. And then we should recall that in neutral atoms only. Our atomic number is also equal to our number of protons. So looking at our symbol, we can say that A is equal to 198 for a mass number of our platinum. It's given to us in the left hand superscript. So we know it's 1 98. And so therefore we can go ahead and calculate our number of. Well next we actually want to find our number of protons. So we're going to take our z value, which is in our left hand subscript equal to 78 A. K. A. Our atomic number because we recognize that we don't have a charge on our platinum isotope, it's neutral. And so we would say that because platinum is neutral isotope. Therefore we say that Our number of protons is also equal to 78. And so now we can go back to our mass number and find our number of neutrons where we're going to take Our mass number 1 98 and subtract that From our number of protons 78 And so this gives us a value or difference of 120. So to complete this example, the number of neutrons is 120 And our number of protons is because again, we stated that we have a neutral isotope of platinum, so everything box in blue represents our final answers. If you have any questions, please leave them down below, and I will see everyone in the next practice video.