in this video we're going to focus on rutherford's gold foil experiment now in this experiment he wanted to test the plum pudding model to see if it was accurate if it was a good representation of the atom and in order to carry out this test he needed a source of alpha particles and so he used a radioactive element such as radium which naturally decays and emits alpha particles so he enclosed it in a container with a tiny opening and thus he got a beam of alpha particles coming out through it now an alpha particle is the same as the helium nucleus it's basically a helium particle with a two plus charge it consists of two protons and two neutrons so that's an alpha particle now what he did with these alpha particles is that he beamed it on a gold foil now this gold foil was surrounded by a detector which looks something like this my draw is not perfect but you get the picture now the this particular detector was coated with a fluorescent substance so when the alpha particles were to hit it it would flash now what he realizes that many of the alpha particles went straight through the gold foil however some of them bounce back while others were deflected at large angles and so he came up with some very important conclusions based on what he saw and he realized that the plum pudding model couldn't be correct now let's talk about some of those conclusions imagine if this circle represents an individual atom the fact that most of the alpha particles went straight through the gold foil what conclusion do you think ernest rutherford came up with since most particles went through the atom or the atoms of the gold foil he concluded that the atom must be mostly empty space now there was something else that he came up with the fact that some of the alpha particles bounced back he realized that there must be a very dense center which we know to be the nucleus the second thing that he realizes that some of the alpha particles they were deflected at large angles now remember the alpha particle consists of two protons two neutrons so the alpha particle has a plus two charge now we know that opposite charges attract if you have a proton next to let's see an electron these two they they're going to fill a force of attraction but like charges they repel each other so if you have let's say two protons next to each other they will feel a force of repulsion and so they're going to move apart now the fact that some of these alpha particles were deflected away from the nucleus indicated that they must have the same charge as the alpha particle so he concluded that at the center you have a region of dense positive charge and so these conclusions were pretty much accurate for the atom the atom is mostly empty space and we do have a nucleus that contains positive charge now this experiment doesn't identify the presence of neutrons but it does tell us that the nucleus is positively charged due to the protons that are in it and so those are the things that ernest rutherford came up with through this experiment so to review he discovered that the atom is mostly empty space due to the fact that many of the alpha particles went straight through the gold foil experiment but the fact that many of them were deflected at large angles show that there had to be a very dense center with positive charge known as the nucleus today so that's a summary of rutherford's gold foil experiment so that's basically it for this video and for those of you who like it feel free to subscribe to this channel for more educational content so thanks again for watching