Roughly speaking the mass of a proton is approximately one Mass of whether it's an atom or the constituents of an atom Of a hairy number here, 1.660540, why did they define it that way? And the answer to your question is, this definition makes it a lot cleaner when we think about the The other thing you might appreciate is this feels like a bit To appreciate it you could write it out, it would be zero point and then 26 zeros and then you would have one Your first reaction, which wouldīe an appropriate reaction, is that wow, 10 to the negativeĢ7 power is very small. So when you see something like this, you might have a few reactions. Mass unit is defined as 1.660540 times 10 to the negative 27 kilograms. So how does a unified atomic mass unit connect to our units of mass that we might use on a larger scale like, say, grams or kilograms. And more recently, the more modern version of this is the unified atomic mass unit, that is denoted by justĪ U instead of an AMU. I'll write it here,Ītomic, atomic mass unit, and it's historically denoted as AMU. How do we measure massĪt such a small scale? Well to do that the chemistry community has historically used somethingĬalled an atomic mass unit. And this video is going to focus on mass. In a few seconds how small of a scale it is, we're going to have to have So if we're going to operateĪt this small of a scale, and we're gonna appreciate Predictions about what will happen, and make things that are We can then begin to understand the universe in which we live in, the scale in which we live in, and even be able to make Thinking about the atomic, and even the subatomic scale. That I've always found amazing about chemistry, it's an entire field of science that we as human beings have developed to actually understand what is happening in an almost unimaginably small scale.

Mass of a hydrogen atom