Capturing and Transmitting Energy

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Electromagnetic Wave Noun

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[ih-lek-troh-mag-net-ik weyv]

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Electromagnetic Wave

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A wave of oscillating electric and magnetic fields that travels through space, carrying radiant energy away from its source.

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Example: This diagram shows the electromagnetic spectrum, arranging waves like radio, microwaves, and X-rays by wavelength. It highlights that visible light is one type of electromagnetic wave.

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Photon Noun

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[foh-ton]

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Photon

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A fundamental particle representing a quantum of light or other electromagnetic radiation, carrying energy proportional to its radiation frequency.

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Example: This diagram shows that when an electron in an atom moves from a high energy level to a lower one, it releases a packet of light energy called a photon.

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Intensity Noun

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[in-ten-si-tee]

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Intensity

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The measure of electromagnetic radiation's power transferred per unit area, which decreases as the distance from the source increases.

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Example: As light energy travels away from a source like a bulb, it spreads out, causing its intensity (brightness) to decrease with distance.

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Transmission Noun

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[trans-mish-uhn]

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Transmission

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The process by which electromagnetic waves pass through a medium or object without being absorbed or reflected by it.

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Example: This image shows how energy is transmitted from the Sun to the Earth in the form of radiation waves.

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Reflection Noun

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[ri-flek-shuhn]

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Reflection

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The change in direction of an electromagnetic wave at an interface, causing it to return into the original medium.

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Example: A beam of light from a source hits a mirror and bounces off, showing how the angle of incidence equals the angle of reflection.

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Absorption Noun

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[ab-sawrp-shuhn]

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Absorption

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The process where the energy of electromagnetic radiation is taken up by matter, often converting it into thermal energy.

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Example: When white light passes through a gas like neon, the gas absorbs specific wavelengths (energies) of light, creating black lines in its absorption spectrum.

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Fluorescence Noun

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[floo-uh-res-uhns]

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Fluorescence

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A phenomenon where a material absorbs light at one wavelength and then re-emits it at a longer, lower-energy wavelength.

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Example: An atom absorbs high energy (like UV light), making an electron jump to a higher level. When it falls back, it emits lower-energy visible light.

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Photovoltaic Cell Noun

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[foh-toh-vol-tey-ik sel]

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Photovoltaic Cell

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An electronic device designed to convert light energy, typically from the sun, directly into electricity through the photovoltaic effect.

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Example: Sunlight hits a photovoltaic cell's semiconductor layer, which converts the light energy into electricity to power devices like a light bulb.

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Semiconductor Noun

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[sem-ee-kuhn-duhk-ter]

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Semiconductor

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A material with electrical conductivity between a conductor and an insulator, essential for manufacturing electronic components like solar cells.

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Example: This diagram shows a semiconductor's energy structure. A small energy gap separates electrons in the lower 'valence band' from the upper 'conduction band'.

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Solar Panel Noun

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[soh-ler pan-l]

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Solar Panel

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A device composed of multiple linked photovoltaic cells that absorb sunlight and convert it into usable electrical energy.

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Example: This diagram shows a solar panel capturing energy from the sun. An inset reveals how positive and negative silicon layers create an electrical current to power a lightbulb.