PROTON CHARGE QUANTITY PLUS

So the subscript is the atomic number and that's Z, and the superscript is the mass number and that's A. Alright, so mass number is red and let me use a different color here for the atomic number. And I'll use red here for mass number so we can distinguish.

PROTON CHARGE QUANTITY PLUS

So in the nucleus there's only one proton and zero neutrons, so one plus zero gives us a mass number of one. And for protium, let's look at protium here. So A is the mass number, which is equal to the number of protons, that's the atomic number which we symbolized by Z, plus the number of neutrons. The mass number is the combined number of protons and neutrons in a nucleus, so it's protons and neutrons, and it's symbolized by A. So let me move down here so we can look at the definition for the mass number. So the subscript is the atomic number which is one, because there's one proton in the nucleus, and then for the superscript, we're going to write in the mass number.

And so the symbol that we'll draw here for protium is going to have the element symbol, which is, of course, hydrogen, and then down here we're going to write the atomic number. How do we distinguish between the different isotopes? Well we're going to write little symbols to represent these isotopes. And so those are the isotopes of hydrogen. Let me go ahead and draw the two neutrons here in the nucleus. So tritium has one proton in the nucleus, one electron outside the nucleus, and we draw that in here, and it must differ in terms of number of neutrons, so tritium has two neutrons. Finally, our last isotope, which is tritium. Deuterium is still hydrogen, it's an isotope. We're talking about atoms of a single element. And that's important because if you change the number of protons, you're changing the element, and that's not what we're doing here. Notice though, that they have the same atomic number, they have the same number of protons in the nucleus. So isotopes have different masses because they differ in terms of number of neutrons. So deuterium has one neutron and since neutrons have mass, deuterium has more mass than protium. I'll use blue here, so neutrons are going to be blue. So let me go ahead and draw in deuterium's one neutron. Deuterium is hydrogen, so it must have one proton in the nucleus and it must have one electron outside the nucleus, but if you look at the definition for isotopes, atoms of a single element that differ in the number of neutrons, protium has zero neutrons in the nucleus. Let me go ahead and write deuterium here. So let's talk about the next isotope of hydrogen. That differ in the number of neutrons in their nuclei. An isotope, isotopes are atoms of a single element. So this is protium and let's talk about isotopes. So this is one, this one version of hydrogen. So this isn't actually what an atom looks like, but it's a very simply view that helps you get started.

I'm going to draw that one electron somewhere outside the nucleus and I'm going to use the oversimplified Bohr model. So there's my one proton in the nucleus, and we're talking about a neutral hydrogen atom, so there's one electron. We know the atomic number of hydrogen is one, so there's one proton in the nucleus.

So let's go ahead and draw an atom of hydrogen. In a neutral atom, the number of protons is equal to the number of electrons, because in a neutral atom there's no overall charge and the positive charges of the protons completely balance with the negative charges of the electrons. So it's right here, so there's one proton in the nucleus of a hydrogen atom. So for hydrogen, hydrogen's atomic number is one. So we're going to talk about hydrogen in this video. And you can find the atomic number on the periodic table. So the atomic number is symbolized by Z and it refers to the number of protons in a nucleus. There are ways it can happen, but they are not the normal course of events. So you do not usually have one isotope changing into another isotope of the same element. So, it is not possible to give you a general answer other than to say that the isotopes of an element form in one or more of the above ways, but each isotope of an element may or may not form in a similar way as other isotopes.Įxcept as listed above, an atom that is not radioactive never changes its number of neutrons. There are a few other ways, but they are not all that significant.Įach isotope (more properly called a nuclide) has its own way(s) in which it is formed. Being changed from one type of atom to another by high energy nuclear reactions, such as having a neutron slam into the nucleus at an extremely high velocity. With the exception of the hydrogen and helium that were formed shortly after the Big Bang event, elements mainly form in the following ways:Ĥ.

Proton charge quantity