How many electrons are necessary to produce a charge of -11.0 C? What is the mass of this many electrons?

Video transcript

welcome back everyone in this example. We need to calculate the number of electrons needed to produce a charge of negative two columns and calculate their mass. So calculate the electron's mass. So we have a two part question. So this is going to be part one. Finding the number of electrons and part two is calculating the mass of these electrons. So beginning with part one, we're going to use the info from the prompt where we're given that charge of negative 2. columns. And so because we want to figure out our number of electrons needed, we should Understand that electrons would be our final unit. So we should recall the conversion factor that one electron has a charge of negative 1.60 times 10 to the negative 19th power columns. And so I'm sorry this is columns. So now we're able to recognize that we can cancel out our units of columns leaving us with electrons as our final unit, which is what we want. And this is going to give us a total number of electrons needed of 1.25 times 10 to the positive 19th power electrons. But we can go ahead and round this to two sig figs As 1.3 times 10 to the 19th power electrons. And so this would be our answer for part one as our number of electrons needed to produce that negative two column charge. So moving on to Part two of our prompt, we need to figure out the the mass of these electrons. So we're going to use that answer from above 1.3 times 10 to the 19th power electrons. And we're going to recall that Because we need to figure out the mass of these electrons that are final unit should be gramps. And so we should recall the conversion factor that we have for one electron, a mass a standard mass of 9.10 times to the negative 28th power gramps. And so this allows us to now cancel out our units of electrons leaving us with g as our final unit. And what we're going to get here Is a value of 1.1 times 10 to the negative 8th power gramps. So this is going to be our mass of electrons. So this would be our answer for part two here, highlighted in yellow as well. And these two multiple or these two answers that we've calculated in yellow are our final answers and correspond to the multiple choice option C. So everything highlighted in yellow represents our final answers. I hope that everything that I explained was clear. But if you have any questions, please leave them down below and I will see everyone in the next practice video