What is the difference between an atom's atomic number and its mass number?

Video transcript

Hello everyone. So in this video we're being asked for the correct statement about atomic numbers and mass numbers of an atom. So usually when we represent this we have a three factor sort of representation. So we have an X. And then over to the left side we have an A. And then we have an X. So we have some element here. Some values here. So what this big X represents is going to be the elemental simple. Then our capital A here, that's going to be our mass number. And then this little X over to the left is going to be our atomic number. Alright. They're kind of breaking apart and recalling what each means. Well for our atomic number that represents the number of protons and their number of protons will then equal to the number of electrons. And that's just how chemistry works here. And then for our mass number, that's equal to the number of protons plus our number of neutrons. Alright, so then once we have broken this down we can kind of match up with the statements and then represents. What we have just explained is going to be statement B which reads that the atomic number is equivalent to the number of protons. While the mass number is equivalent to the sum of the protons and the number of neutrons. So B is going to be the correct statement about atomic numbers and mass numbers of an element. Thank you all so much for watching