UTF-8Light can heat matter 光可以加熱物質
How does light energy convert into heat energy? When a photon is absorbed by an electron, the electron will be excited to a higher energy level. The higher energy level is usually unstable, hence it will stay for a short while and fall into a lower level if it receives no more energy. When it falls to a lower level, two things can happen. The first is that it emits a photon. The atoms do not get heated because the excess energy is released in the form of light. The second is that it transfers the excess energy into the kinetic energy of the nucleus (if the electron transitions between atomic orbitals) or the nuclei (if the electron transitions between molecular orbitals), causing heating. This is called radiationless transition. The probability of raditionless transition depends on the physical properties of materials.
Note: the above discussion is limited to only heating caused by photons of frequencies higher than infrared. Infrared light and microwave can interact with the molecular vibrations and rotations, and heat materials by increasing the vibrational and rotational energy of the molecules.6.04.0prism.gif4040content40content40content11111org.concord.mw2d.activity.AtomContainerlight123$0.mmlfalseorg.concord.modeler.PageElectronicStructureViewer03-10.0-8.020160180org.concord.modeler.PageBarGraphorg.concord.mw2d.models.MolecularModel0Kinetic Energy/ParticleTemperature (K)10000.00470230true510true-100000.02000.052.691241726279261org.concord.modeler.PageSliderorg.concord.mw2d.models.MolecularModel04.60.010.050Intensity of Light Source30070falsetrue{value="10.0", label="Strong"}{value="0.0", label="Weak"}Intensity of Light Sourceorg.concord.modeler.PageSliderorg.concord.mw2d.models.MolecularModel00.99999999834431530.100000001490116121.09Simulation speed10060falsetrue{value="0.9999999983443153", label="Fast"}{value="0.09999999983443153", label="Slow"}Simulation speed of light-matter interactionsorg.concord.modeler.PageCheckBoxTurn on light sourcetrueorg.concord.mw2d.models.MolecularModel0Turn on light sourceorg.concord.modeler.PageCheckBoxK. E. Shadingorg.concord.mw2d.models.MolecularModel0K. E. Shading116.01111true116.0116.011