In this video, David explains how an atom can absorb and emit photons with particular values of energy and how to determine the allowed values.

According to Bohr's model, an electron would absorb energy in the form of photons to get excited to a higher energy level as long as the photon's energy was equal to the energy difference between the …

Electrons only exist at specific, discrete energy levels in an atom. If an electron absorbs a photon with energy equal to the difference between two energy levels, the electron will transition to the higher …

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Electron shells consist of one or more subshells, and subshells consist of one or more atomic orbitals. Electrons in the same subshell have the same energy, while electrons in different shells or subshells …

Each of the categories above is called a trophic level, and it reflects how many consumption steps separate an organism from the food chain's original energy source, such as light.

The Bohr model explains these different energy levels that we see. So, when you look at the line spectrum of hydrogen, it's kind of like you're seeing energy levels.

We can interpret that both ways that electrons can be exciting and that we're going to excite them into higher energy levels. Or we're going to think about what happens when they get unexcited, when …

We can think of the incident light as a stream of photons with an energy determined by the light frequency. When a photon hits the metal surface, the photon's energy is absorbed by an electron in …

The model shown here actually combines Niels Bohr’s original idea of electrons orbiting the nucleus at specific energy levels with later ideas from the quantum mechanical model. These include the pairing …