Why does heat excite electrons

The most stable electron configuration is that of a noble gas, due to the fact that its valence shell is filled. For helium, that means two valence electrons a duet in the 1s sublevel, and for the rest it means eight valence electrons an octet in the outermost s and p sublevels. David M. Stefan V. An electron absorbs energy when it goes from a ground state to an excited state.

Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home Physics Why does heat excite electrons? Ben Davis February 22, The distances between levels are also unique to each atom, which means the colors they emit - the emission spectrum - when they're heated are unique and identifiable. Of course, deGrasse Tyson's real point in that tweet, I think, was to express admiration for the manner and clarity which the information is presented, something I'm suddenly self-conscious about looking back on that last paragraph.

Wikipedia is more concise:. When the electrons in the atom are excited, for example by being heated, the additional energy pushes the electrons to higher energy orbitals. When the electrons fall back down and leave the excited state, energy is re-emitted in the form of a photon. The wavelength or equivalently, frequency of the photon is determined by the difference in energy between the two states.

These emitted photons form the element's emission spectrum. The frequencies of light that an atom can emit are dependent on states the electrons can be in. When the electron falls back to its ground level the light is emitted. As you mentioned, light is emitted when an excited electron transitions energy levels back to its ground state.

One way to excite an electron, like you said, is by absorbing photons of light. Glow in the dark toys are an example of this- you have to hold them up to a light to charge them, and they are made of special phosphorescent materials in which the electrons fall back to the ground state slowly so that the glow is sustained.

Light is not the only way to excite an electron. Thermal energy can also raise the electron to a higher energy state, which is what is happening in your metal salt burning experiment. The cause of excitation is the heat, and light is emitted when the electron returns to the ground state.

Each metal salt has a characteristic light color that it releases. Metal salts can be incorporated into fireworks to give them color. In addition to light and heat, another way that electrons can get excited is through the direct transfer of energy that occurs when the electron collides with another atom or electron. I hope this answers your question, please feel free to contact me if you have more.