The Stern-Gerlach Experiment in lauded in textbooks around the world for its contributions to the world of quantum physics. But for a few years, scientists unknowingly praised it for proving the wrong thing! Because instead of proving...

The Fine Structure Constant is one the strangest numbers in all of physics. It’s the job of physicists to worry about numbers, but there’s one number that physicists have stressed about more than any other. That number is 0.00729735256 -...

The wave model of the electron can be used to explain the Bohr model. Electrons are found in certain orbits because they interfere with themselves and create standing waves. When the wavelengths don't match up with a whole integer they...

In this video Paul Andersen describes the major parts of an atom and explains how the Bohr Model more accurately represents the location of electrons around the nucleus. Niels Bohr refined the Rutherford model to account for spectra.

In this video Paul Andersen explains how the atomic model has changed over time. A model is simply a theoretical construct of phenomenon and so when we receive new data we may have to refine our model. Ionization energy data resulted...

This constant represented by the Greek letter alpha is just a dimensionless number, so no matter what units you use, it will always have the same value, about 1/137. If it was different by just 4%, life may not...

When Ernest Rutherford realized that atoms have a heavy nucleus, he hypothesized that the way the moon orbits earth is the same as the way an electron orbits the nucleus of atoms. We now know an atom would...

While While the Bohr model of the atom is not the most accurate model we have today, it can help up show a lot of valuable information about the atom. Bohr models can show the protons and neutrons in the nucleus along with the number of...

In a hydrogen atom, the electron is bound to the nucleus, so its energy is negative. This shows that it is in a bound state. When there is negative energy, it means that the electron is stable. It is inside the atom because its...

What is an atom? And what is it made of? In this video, I will be introducing you to the atom. We will also look at concepts like atomic mass, elements and isotopes.

Niels Bohr's model of the atom introduced the idea of quantised orbits for electrons. In these, electrons occupy stable energy levels and either give off or take in photons when they move between these levels. This model was able to...

Bohr's model of the atom says that an electron's energy is set by its orbit around the nucleus. Bohr said that electrons have specific, quantised levels of energy, and that the size of the orbit affects the energy...

Bohr's atomic model postulates that the radius of an electron's orbit around the nucleus is determined by the concept that electrons travel in quantised orbits with distinct and well-defined radii. According to the model, the angular...

Why does chemistry happen?? Why do ions form?? Why do elements bond together?? These are all important questions and the answer comes back to one very important principle in chemistry and that is element stability. Elements are stable...

Coulomb’s Law is one of the most important laws when it comes to atomic structure and being able to understand and explain atomic properties. It helps to relate the force between two charged particles and can be represented by the...

The periodic trend for atomic size is that the size of the atom gets bigger as you go down the periodic table and from right to left across the periodic table. This trend is sometimes referred to as atomic radius as there is a direct...

This video explains how the different particles in an atom have charges, how the different particles affect the overall charges of an atom, and how atomic models are created.

This live-action video program is about the word models. The program is designed to reinforce and support a student's comprehension and retention of the word models through use of video footage, photographs, diagrams and colorful,...

Practice REAL problems from actual past IIT/JEE exams with Professor Dave!

Introductory video to the hydrogen line spectrum, which in part led to the initial development of quantum mechanics.<br/>

Practice REAL problems from actual past IIT/JEE exams with Professor Dave!

With the Bohr model we start to get a better sense of the nature of matter, particularly the way light interacts with atomic matter such that we can see it. But how do we do calculations regarding these interactions? Let's practice now!

Assuming a circular orbit of the electron about the nuclear proton in the Bohr model of the hydrogen atom, determine the speed of the electron.

So Max Planck kicked things off, but how does the story of modern physics continue? With none other than your favorite scientist and mine, Albert Einstein! He did more than just stick his tongue out and have crazy hair. He elucidated the...