hello everybody my name is Iman welcome back to my YouTube channel we've made it to the third video in our high yield MCAT General chemistry playlist this video is on B's model of the hydrogen atom part one now before delving into B's model it's really important for us to understand the context in which it was developed and so at the turn of the 20th century the Rutherford model proposed that atams have a small dense nucleus and electrons kind of orbited around it much like planets orbit the sun however classical physics couldn't explain why electrons didn't simply spiral down into the nucleus Here Comes Max plank Max Plank's quantum theory introduced the idea that energy is not continuous but rather comes in discrete packets called Quantum all right so Plank's quantum theory states that energy emitted as electromagnetic radiation from matter exist in discrete bundles called Quant and it can be expressed using this equation right here this equation says that energy is equal to Plank's constant Plank's constant is 6.62607004 so energy equals Plank's constant multiplied by frequency so when an electron transitions between energy levels it emits or absorbs a photon with energy that's equal to the difference between the energy levels now this expression can be Rewritten in another way all right and it can be Rewritten in a different way because we know that frequency equals speed of light divided Lambda which is wavelength so frequency is equal to the speed of light divided by wavelength so we can replace frequency with this definition here and then we would get that energy equals Plank's constant multiplied by the speed of light divided by wavelength and the speed of light is about 3 * 10 8 m/ second now this was the ground work that Neils bore built upon in 1913 Neil's bore in integrating Rutherford's nuclear model and now Plank's quantum concept he proposed a new model of the atom specifically applied to hydrogen which is the simplest atom bore suggested that electrons orbit the nucleus in specific fixed orbits or shells and that each orbit actually corresponds to a certain energy level so unlike what classical physics suggested bora's model stated that electrons in these orbits do not radiate energy they only emit or absorb energy when they're jumping from one orbit to another now the energy of an electron in B's model is given by this formula right here energy is equal to minus RH this is a constant this is rid Burg's constant and it's equal to 2.18 * 10 the to the -8 je per electron and N here is the principal quantum number and it's divided by N2 specifically now the negative sign here indicates that the energy of the electron is lower when it is in an orbit that's closer to the nucleus now we're going to get into a lot of detail about B's model specifically the hydrogen atom but before we get there I want to point out the significance of bores model and this is going to set the stage for part two B's model was a significant advancement because it explained the discrete lines that scientists observed in the hydrogen spectrum they didn't observe continuous lines in the absorption and emission spectrum for the for the hydrogen atom instead they saw discrete lines and each of those lines correspond to a transition between energy levels further indicating that energy is quantized not continuous all right and this is actually the topic of the next two parts for B's model of the hydrogen atom so definitely stay tuned now something else is though although later models would supersede B's model and they would introduce Concepts like electron Spin and of course the probalistic nature of electron positions B's model was very crucial in the development of quantum mechanics and of of course our understanding of atomic structure it marked the first Quantum model that explained the stability of the atomic structure and the emission of light in quantized energy packets and pretty much provided a stepping stone towards a more accurate and comprehensive quantum theory all right please stay tuned for part two and three for this topic let me know if you have any questions comments concerns down below other than that good luck happy studying and have a beautiful beautiful day future doctors