Author Archives: hangtime
Rydberg Equation
Rydberg's equation allows you to calculate the energy of each of the orbitals of a hydrogen atom. Not enthralling stuff, no doubt, but you can use it to calculate the absorption and emission spectra of atoms, if you're into that.
What Are Absorption & Emission Spectra
This video explains what the heck these "spectra" are, and shows you how to solve the most common problem type associated with these, where you're given the energy levels of an atom (usually hydrogen) and then are asked the frequency or energy of a photon which would excite an electron to jump from one level to another.
This chapter explains how to calculate the energy, wavelength and frequency of photons which can be absorbed or emitted by electrons in hydrogen, using orbital energies or Rydberg's equation.
Electron Volts
A strange little unit of energy that's only used when physicists are talking about photons and particles, this video explains what they are and how to convert to them from Joules. Btw, hilarious science jokes in this video.
Photon Energy & Planck's Constant
By the end of this video, my hope for you is that every time you see the words "photon" and "energy" in the same sentence -- even if you're in the grocery store -- you'll immediately think of the equation E=hf.
The Electromagnetic Spectrum
Most physics and chemistry teachers will expect you to know off the top of your head whether red or purple light has a longer wavelength, what the "visible spectrum" is, and how X-rays and UV-rays stack up. This video covers the whole E&M Spectrum, and gets you up to speed with what very well might be a question on your next test.
Frequency & Wavelength of Light
This video covers what wavelength and frequency are, and also how to calculate them from the equation: speed of light = (wavelength) x (frequency).
This chapter covers wavelength, frequency, electromagnetic spectrum (E&M), Planck's constant, energy of photons, and electron volts (eV, keV).
Quantum Numbers
This is that thing where you have to assign numbers -- sort of like x-y coordinates except there's four of them -- to each electron in an atom whilst obeying the Pauli Exclusion Principle: the principal quantum number, azimuthal quantum number, magnetic quantum number, and spin.
Sort of like the quantum version of x-y coordinates for electrons, these four coordinates give the shell, orbital type, sub-orbital and spin of every electron in an atom (Pauli Exclusion Principle).
Paramagnetic vs Diamagnetic Atoms
Paramagnetism and diamagnetism are just vocab for the final step that you have to do on many electron orbital diagrams, which is basically to go through and say whether all the little arrows have roommates or not.
Orbital Box Diagrams, Hund's Rule & Pauli Exclusion
Orbital box diagrams are the electron configuration problems where you have to draw each electron out as a little arrow inside a box. Hund's Rule tells you the electrons don't like roommates, and the Pauli Exclusion Principle tells you that if an electron has to have a roommate, it wants one with opposite spin.
Ion Electron Configurations
This video just covers a minor variation in electronic configuration problems, which is to do the configuration for ions instead of elements. Hint: they're all noble gas configurations.
Noble Gas Electron Configuration Notation
Once you've done a few electronic configurations, you start noticing that they can get really long, and that everything except the last orbital or two is always the same. Which brings us to "noble gas notation", which basically lets you skip over the boring stuff (the inner shells) and just write the much shorter configuration of the outer shells.
Electron Configuration Shortcut Using Periodic Table
Approximately 80% of the students I've tutored prefer to use this method to do electronic configurations of atoms. It's a bit trickier if you think about it, but the key is to not think to hard and instead plug and chug. The main feature of this shortcut is that it saves you from memorizing anything, which is why it works for so many students.
Basic Electron Configurations
No electronic configuration problem is exactly "basic", but this video does cover the more "straightforward" ones without any tricks. It covers the basic process for doing electron configuration problems, and gives you the best way to memorize the order that the s-, p-, d- and f-orbitals get filled, which is really half the battle.
Also covered are Hund's Rule, the Pauli Exclusion Principle, and shortcuts you can use to streamline electronic configurations.
Atomic Radius (Radii)
This video shows you the two main problems you need to know for this topic. The main one is knowing how to use the periodic table to figure out the relative size of one atom versus another. The other is comparing the size of an ion to the neutral atom of the same element.