Plug this in for our radius, five point three timesġ0 to the negative 11. And finally, for n isĮqual to one, this was our allowed radius so we can Is nine point one one times 10 to the negative 31st kilograms.

The electron so m was the mass of our electron, which Times 10 to the negative 34 divided by two pi times m. One times Planck's constant, six point six two six One, so we're talking about n is equal to one so we're This radius and we're gonna plug it in down here and then we know what these other numbers are. The velocity of this electron cause we're gonna take So if we plug in some numbers here, we can actually solve for Using Bohr's assumption for quantised angular momentum and the classical idea Times Planck's constant divided by two pi m times r, and we figured this out We derived was the velocity is equal to the integer n If you go back to the previous video, you'll see the equation that In the previous video, weĪlso calculated the velocity or we came up with anĮquation that you could use to calculate the velocity So this is, this number right here, is the radius of the smallest In the ground state, in the lowest energy state for hydrogen. And so when n is equal to one, we said this was an electron Is one so r one is equal to five point three times 10 to Radius using the Bohr model is equal to one squared times r one. So r for any integer n isĮqual to n squared times r one, for example, if you wanted And we also derived this equation, right. Point three times 10 to the negative eleventh meters, Radius of this circle, and we said this was equal to r one. And in the last video, weĬalculated this radius. Which gives our electron a velocity tangent to our circle, which we said was v in the last video. And so we just assumed the electron was going in this direction So counter-clockwise around And even though this is not reality, the Bohr model is notĮxactly what's happening, it is a useful model to think about. Model of the hydrogen atom, which has one proton in its nucleus, so here's the positiveĬharge in the nucleus, and a negatively chargedĮlectron orbiting the nucleus. It is using the more flexible common speech definition of touch in a way that it it doesn't apply.ĭidn't watch the last video because there was too much physics, I'll just quickly summarize So in the end the idea that matter is just empty space and things don't touch is not an accurate statement. It is at the point where the Van der Waals force and the force from the Pauli exclusion principle cancel each other out it when your finger is technically touching the table. As the atoms in your finger and the table get even closer the Pauli exclusion principle begins to push the electrons in the atoms of your finger and the table apart. As your finger gets closer to the table there is a slightly attractive force between the outer electrons in the atoms in your finger and the table and the nuclei in these atoms, this is called the van der Waals force. Saying that that matter particles don't ever occupy the same space and interact via fields but this is also true at every day macroscopic scales as well.įrom a scientific perspective when you touch the surface of a table the electromagnetic fields and the Pauli exclusion principle come into play.

Fundamental particles are essentially points with no volume that have associated fields that may or may not interact. When you start to look at things at an atomic and sub-atomic scales this idea starts to break down. What is empty space? The concept of something occupying space come from our everyday concept of physical objects occupying a volume of space and that there is something there. Saying this you are using the loose idea of what empty space is and what it means to touch something in everyday life and not a technical scientific definition of what empty and touching means. The idea that atoms are mostly empty space or that nothing touches at an atomic level is not really accurate.

Bohr model of nitrogen atom