The natural abundance of ³He is 0.000137%. (b) Based on the sum of the masses of their subatomic particles, which is expected to be more massive, an atom of ³He or an atom of ³H (which is also called tritium)?

Video transcript

Hey everyone in this example being to determine the heavier atom between carbon 14 and nitrogen 14 by comparing their total masses of their subatomic particles. So we want to go ahead and outline our subatomic particles for carbon we would recognize that carbon 14 corresponds to atomic number six on our periodic tables. When we find carbon in Group four A across period two. And because it has atomic number six, we would say that therefore because this is a neutral isotope, we have six protons and six electrons. And so to find our total number of neutrons. We're going to take our mass number 14 and we're going to subtract that from our number of protons six protons to equal eight neutrons. So we find this because we would recall that mass number is equal to our number of protons plus our number of neutrons. And so we're going to find the weight of our atom by taking our six protons and multiplying that by the constant for protons, which is equal to a value of 1.67262 times 10 to the negative 27th power kilograms for protons. We're then going to add this to our six electrons, multiplied by their constant of 9.1093837 times 10 to the negative 31st power kilograms of electrons. And this is then also going to be and I'll just go ahead and make more room here. This is going to be then added to our quantity for our neutrons. Where we stated that we have in carbon 14 8 neutrons, which is multiplied by the neutron constant of 1.67493 times 10 to the negative power kilograms for our neutrons. And this some here is going to equal a value of 2.3441 times 10 to the negative power kilograms. So in comparison, we're going to compare our carbon or sorry, or nitrogen 14, which according to our atomic number for nitrogen on the periodic table, which we see is equal to a value of seven, corresponds to therefore seven protons and seven electrons. And so we would find the mass number, We're sorry. We would find the number of neutrons for nitrogen 14 by taking our mass number 14 and subtracting that from our seven protons to give us a value of seven neutrons. And so now we want to find our mass of our nitrogen 14 by taking our seven protons and multiplying it by our constant for protons 1.67262 times 10 to the negative 27 power kilograms for protons, we're then going to add this to our seven electrons which are going to be multiplied by the constant for electrons. We recalled above as 9.1093837 times 10 to the negative 31st power kilograms of electrons. And then added to our number of neutrons, which we calculated above as seven multiplied by the constant for neutrons equal to 1.67493 times 10 to the negative power kilograms of neutrons. And this sum here gives us a value equal to 2.3439 times 10 to the negative 26 power kilograms. And so comparing these two masses that we've calculated for both nitrogen 14 and carbon 14, we can see that we have a larger mass here, and so this is going to be the larger or heavier. So we can just erase this to say heavier. Actually, this is going to be our heavier atom. And so this will be our final answer. To complete this example that are heavier atom is going to be our isotope carbon 14. So I hope that everything I went through is clear. If you have any questions, please leave them down below and I will see everyone in the next practice video.