Video Transcript

Hi my name is Janice and I teach science here in Clearwater, Florida. I'm here to talk to you today about how you calculate ionization energy of an element. Well ionization energy is based on something called atomic number and atomic number is the number of protons or neutrons that, excuse me protons or electrons found inside of an atom. So where we typically go to find that information is on the periodic table and in the periodic table each element will be in a box and that box will usually look something like this. It will have a hole number, let's talk about helium. It will have the symbol for that, helium is He and then it will usually have a number at the bottom that is in digital form and this number is typically about twice the size of that number. So the atomic number is going to be the whole number, that's what we want to look for. So the way that we calculate ionization energy is we take the atomic number and we subtract one. And then, we square that answer and then we multiply it by 13.6. So in the case of helium whose atomic number is 2, we would subtract 1, 2 minus 1, we would square that. So 2 minus 1 is 1 squared. We would multiply that by 13.6. Now 1 squared is 1 times 13.6 and that would measure ionization energy in electron volts. So the ionization energy of helium would be 13.6 electron volts. And that's how you calculate the ionization energy of an atom. I'm Janice. Have a great day.