https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:waves/x1baed5db7c1bb50b:electromagnetic-waves/v/the-electromagnetic-spectrum 2025-07-01T10:10:08.145512912Z The electromagnetic spectrum Light is an electromagnetic wave. All electromagnetic waves travel at the speed of light in vacuum. The frequency of a light wave corresponds to its color. The amplitude of a light wave corresponds to its brightness. Visible light is only a small part of the electromagnetic spectrum, which also includes radio, microwaves, infrared, ultraviolet, X-rays, and gamma rays. These different frequencies of electromagnetic waves have different applications. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/e317d099-29e7-41b4-a05c-8f7178545f8b_1280_720_base.png The electromagnetic spectrum Light is an electromagnetic wave. All electromagnetic waves travel at the speed of light in vacuum. The frequency of a light wave corresponds to its color. The amplitude of a light wave corresponds to its brightness. Visible light is only a small part of the electromagnetic spectrum, which also includes radio, microwaves, infrared, ultraviolet, X-rays, and gamma rays. These different frequencies of electromagnetic waves have different applications. https://cdn.kastatic.org/ka-youtube-converted/iVbuCROYAz4.mp4/iVbuCROYAz4.mp4 523 Electromagnetic waves https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atomic-models-and-periodicity/x2613d8165d88df5e:the-bohr-model-and-atomic-spectra/a/the-electromagnetic-spectrum 2026-06-16T04:13:16.216382129Z Learn and try: The electromagnetic spectrum Learn about electromagnetic radiation and take a tour of the electromagnetic spectrum. article https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atomic-models-and-periodicity/x2613d8165d88df5e:the-bohr-model-and-atomic-spectra/e/apply-the-electromagnetic-spectrum 2026-06-25T14:10:39.916233732Z Apply: The electromagnetic spectrum Apply your understanding of the electromagnetic spectrum in this set of free, standards-aligned practice questions. Emily Cizmas exercise https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/electromagnetic_waves 2024-05-16T01:13:56.718395588Z Electromagnetic waves Electromagnetic (EM) waves are produced whenever electrons or other charged particles accelerate. The wavelength of an EM wave is the distance between consecutive points on the wave with the same phase (e.g. one crest to the next crest). The frequency of an EM wave is how many wave cycles are emitted, or pass a given point, per second. The speed of a wave is equal to its frequency times its wavelength. In vacuum, all EM waves travel at speed c = 3 x 10^8 m/s. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/fa27a4a6-9f11-4533-8d14-5569e37dfdff_1280_720_base.png Electromagnetic waves Electromagnetic (EM) waves are produced whenever electrons or other charged particles accelerate. The wavelength of an EM wave is the distance between consecutive points on the wave with the same phase (e.g. one crest to the next crest). The frequency of an EM wave is how many wave cycles are emitted, or pass a given point, per second. The speed of a wave is equal to its frequency times its wavelength. In vacuum, all EM waves travel at speed c = 3 x 10^8 m/s. https://cdn.kastatic.org/ka-youtube-converted/Je_f4RimfKI.mp4/Je_f4RimfKI.mp4 853 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/tour-of-the-ems-02-radio-waves 2020-06-23T07:22:42Z Radio waves (1888) NASA video https://cdn.kastatic.org/googleusercontent/A5ACZMYyVkUak16wXY1FuXYegPNG7O9-uMpBhNDiu-888zly-E20ypCrCZzM6Fy45cfIx4ijIVBnR4Ri_QEx0pkD Radio waves (1888) https://cdn.kastatic.org/ka-youtube-converted/OzDmEA8x0nQ.mp4/OzDmEA8x0nQ.mp4 219 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/microwaves 2020-06-23T07:22:41Z Microwaves (1930) NASA video https://cdn.kastatic.org/googleusercontent/dpnF1GzKihDefExUBhHxeFWg9t5olYoxMRL-5Rq7ioxohb1Rae7ys20bHSb_uMSP2kN7Cd8_t3TlZerrraMWVA8 Microwaves (1930) https://cdn.kastatic.org/ka-youtube-converted/UZeBzTI5Omk.mp4/UZeBzTI5Omk.mp4 184 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/infrared-waves 2020-06-23T07:22:42Z Infrared waves (1800) NASA video https://cdn.kastatic.org/googleusercontent/b9RykjIGb8SLuKd49X4zqRcV-4mC_69vV8ZZcTrjaUEdbsVJc_ZjRpEG0ZawUhhSQN8QzFxII_MDXoiIh9-GAMo Infrared waves (1800) https://cdn.kastatic.org/ka-youtube-converted/i8caGm9Fmh0.mp4/i8caGm9Fmh0.mp4 323 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/visible-light-waves 2020-06-23T07:22:40Z Visible light (1672) NASA video https://cdn.kastatic.org/googleusercontent/mIE2fNoGNAZk5FP1lw67Ne8HJ51EYDNMdpWjnLpI3IsVgGquUfz6G1dvORa9-uRJtkBjYm3svOcgVA69Ll_fWYbAaA Visible light (1672) https://cdn.kastatic.org/ka-youtube-converted/PMtC34pzKGc.mp4/PMtC34pzKGc.mp4 290 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/tour-of-the-ems-06-ultraviolet-waves 2020-06-23T07:22:42Z Ultraviolet waves (1801) NASA video https://cdn.kastatic.org/googleusercontent/duKsfU_8KbzbUjJFKg5OqzlBOSBTX7sP5lVAtuG8S4ahHYaNZNGTtNkcKxxhr7t-bkGvutGz3RJfV5YoysKKS9lQqQ Ultraviolet waves (1801) https://cdn.kastatic.org/ka-youtube-converted/QW5zeVy8aE0.mp4/QW5zeVy8aE0.mp4 220 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/x-rays 2020-06-23T07:22:41Z X-rays (1895) NASA video https://cdn.kastatic.org/googleusercontent/xOCnLhhnlvvIG3i670bCEgmuJtaRnPnEFRW2LpAE99GkV4T7bgum6WqsG2B0nJHKq1YVMAFev7799ypJ2_2RlGU X-rays (1895) https://cdn.kastatic.org/ka-youtube-converted/CCAYcuCWOnM.mp4/CCAYcuCWOnM.mp4 170 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:uses-of-electromagnetic-waves/v/gamma-waves 2020-06-23T07:22:41Z Gamma waves (1900) NASA video https://cdn.kastatic.org/googleusercontent/m5sv5hYJ4YoM0PW92dvj9ppMaaba_NSmH0TPCnQwXblHDywo57OWksjma_SdYdVRg1BHmriFLa7JywpyZngbfQKJ Gamma waves (1900) https://cdn.kastatic.org/ka-youtube-converted/TA5SLDiIUWs.mp4/TA5SLDiIUWs.mp4 222 Electromagnetic waves https://www.khanacademy.org/science/cambridge-o-level-physics-cie/x0e04e0cb682fb793:electromagnetic-spectrum/x0e04e0cb682fb793:untitled-526/a/electromagnetic-waves 2026-06-16T04:23:47.092153677Z Learn and try: Electromagnetic waves Learn about electromagnetic waves, including visible light waves. Explore the ray model and use it to model different behaviors of light. article https://www.khanacademy.org/science/ms-physics/x1baed5db7c1bb50b:waves/x1baed5db7c1bb50b:electromagnetic-waves/e/apply-absorption-and-reflection 2026-05-01T13:40:34.883034315Z Apply: Electromagnetic waves Apply your knowledge of electromagnetic waves in this set of free, standards-aligned practice questions. Khan Academy exercise https://www.khanacademy.org/science/9th-grade-science-revised-k-to-10-3-terms/xd7ac71d14f11a4d6:1st-quarter/xd7ac71d14f11a4d6:electromagnetic-waves/v/effects-of-different-wavelengths-of-radiation 2022-09-08T02:59:50.812572544Z Effects of different wavelengths of radiation When electromagnetic radiation is absorbed by a material the energy it carries has to go somewhere. When lower energy waves, like radio and infrared waves, are absorbed there can be an increase in temperature of the absorbing material. Higher energy waves, like x-ray and gamma waves, can actually permanently damage or change materials. Learn about the different types of electromagnetic waves and how their energies can influence their effects on objects. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/bd52e997-b4fb-4452-9ae9-87c44d13f84d_1280_720_base.png Effects of different wavelengths of radiation When electromagnetic radiation is absorbed by a material the energy it carries has to go somewhere. When lower energy waves, like radio and infrared waves, are absorbed there can be an increase in temperature of the absorbing material. Higher energy waves, like x-ray and gamma waves, can actually permanently damage or change materials. Learn about the different types of electromagnetic waves and how their energies can influence their effects on objects. https://cdn.kastatic.org/ka-youtube-converted/zH7ZT2tdqQ0.mp4/zH7ZT2tdqQ0.mp4 131 Electromagnetic waves https://www.khanacademy.org/science/modern-physics-essentials/x1bb01bdec712d446:why-light-and-matter-are-two-faced/x1bb01bdec712d446:einstein-s-elegant-equation-to-decode-the-photoelectric-effect/v/photoelectric-effect 2021-07-13T07:08:36Z Photoelectric effect Explaining the photoelectric effect using wave-particle duality, the work function of a metal, and how to calculate the velocity of a photoelectron. Jay video https://cdn.kastatic.org/googleusercontent/gqySkF-QLR1DIapMNaJf4cKjCot4c_Q_bS3RJWhG51wNipkKEBiJhFs4JhcAYKEKpKnBDkaZxVc1anx-qYHe2W04 Photoelectric effect Explaining the photoelectric effect using wave-particle duality, the work function of a metal, and how to calculate the velocity of a photoelectron. https://cdn.kastatic.org/ka-youtube-converted/vuGpUFjLaYE.mp4/vuGpUFjLaYE.mp4 624 Electromagnetic waves https://www.khanacademy.org/science/9th-grade-science-revised-k-to-10-3-terms/xd7ac71d14f11a4d6:1st-quarter/xd7ac71d14f11a4d6:electromagnetic-waves/e/understand-electromagnetic-radiation-matter 2022-08-24T23:02:51.270315507Z Understand: electromagnetic radiation and matter Check your understanding of electromagnetic radiation and matter in this set of free practice questions aligned to NGSS standards. exercise https://www.khanacademy.org/science/9th-grade-science-revised-k-to-10-3-terms/xd7ac71d14f11a4d6:1st-quarter/xd7ac71d14f11a4d6:electromagnetic-waves/v/electromagnetic-radiation-emission 2022-09-08T02:59:50.812572544Z Emission of electromagnetic radiation There are many different processes and phenomena that emit electromagnetic radiation. Humans have taken advantage of many of these processes to develop technologies that use electromagnetic radiation. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/f5b38836-2967-458e-a56a-15153966903b_1280_720_base.png Emission of electromagnetic radiation There are many different processes and phenomena that emit electromagnetic radiation. Humans have taken advantage of many of these processes to develop technologies that use electromagnetic radiation. https://cdn.kastatic.org/ka-youtube-converted/WsSMMeYh8jU.mp4/WsSMMeYh8jU.mp4 321 Electromagnetic waves https://www.khanacademy.org/science/9th-grade-science-revised-k-to-10-3-terms/xd7ac71d14f11a4d6:1st-quarter/xd7ac71d14f11a4d6:electromagnetic-waves/e/understand-emission-of-electromagnetic-radiation 2022-08-24T23:02:51.270315507Z Understand: emission of electromagnetic radiation Check your understanding of emission of electromagnetic radiation in this set of free practice questions aligned to NGSS standards. exercise https://www.khanacademy.org/science/9th-grade-science-revised-k-to-10-3-terms/xd7ac71d14f11a4d6:1st-quarter/xd7ac71d14f11a4d6:electromagnetic-waves/e/light-and-electromagnetic-radiation-questions 2022-05-30T00:23:01.374983084Z Light and electromagnetic radiation questions Questions pertaining to light and electromagnetic radiation rabeehaq exercise