How Are Electrons Kept in Motion Around the Nucleus?


Hi, I’m Robin Higgins, and this is, “How Are Electrons Kept in Motion Around the Nucleus?” Alright, first of all, kudos to you on a good question! So, there’s a couple different parts to this. So, just to review, we can use it as a guide. Our atoms are a nucleus with protons and neutrons, and then circling around it are negatively-charged electrons. Alright, so, the reason that the electrons don’t fly off into space is because the negative charge of the electron is attracted to the positive charge of the proton. So, they’re around the nucleus because opposite charges attract. And so, if electrons and protons are positively charged, they’d be repelled from each other, and we wouldn’t have the same structure of atoms as we do today. And so, this is actually a question that a lot of scientists were asking themselves couple hundred years ago of, “If negative and positive charges are attracted to each other, why aren’t electrons crashing into the nucleus and actually trying to get as close as they possibly can to the positively-charged protons?” And, there’s a couple of answers to that. First of all, understand that all of these rules about electrons have a lot of stuff to do with quantum mechanics. So, unless you want to go and study math for about 15 years, then everything we learn is kind of an approximation. So, one way to view it is, it’s kind of like the Earth traveling around the sun. So, Earth travels around the sun, and Earth has its own speed, or a scientist would say momentum. And so, electrons, they all have something called angular momentum, and what this means is that they have their own direction that they’re moving in, and they have their own energy. And so, just like the Earth doesn’t, you know, get attracted to the sun’s gravity and then fly towards the sun, it just ends up getting hooked in a cycle around. So, that’s one reason. And, the other reason is just basically because of electrons – their own energy. And, there are ton and tons of quantum mechanic reasons why electrons are trapped in certain orbitals, and they can’t escape from those orbitals unless they get energy. And then, the electrons themselves are on different orbitals or energy levels, and so there’s just a bunch of rules that kind of say what electrons can and cannot do, because again, 15 years of math. So, yeah, as a summary, they’re around the nucleus because opposite charges attract. And, think of the Earth traveling around the sun of why they keep in constant motion – they’re attracted, but they’re not going to head for a collision course. I’m Robin Higgins, and this is, ““How Are Electrons Kept in Motion Around the Nucleus?”

Robin Higgins graduated with a B.S in Chemistry from Emory University 2010, and has just recently received her M.S in Chemistry from the University of California Los Angeles.