A neon light is more similar to an incandescent light or a fluorescent light explain how you know?

Answer 1

A neon light is more similar to a fluorescent light because they both glow brightly.

Answer 2

A neon light is much more similar to a fluorescent light.

I know because I have a Ph.D. in physical chemistry, but I suspect you mean "justify your answer," so here goes.

In a gas-discharge light (a neon light), a gas is ionized by an electric potential. Free electrons are then accelerated through the ionized gas. This causes the ions to transition into an excited electronic state. When the ion decays back to the ground state, energy of characteristic frequencies is emitted; the dominant frequencies depend on the gas, the voltage, and the pressure. This is why neon lights are orange-red: the dominant characteristic visible frequencies for neon gas are in the orange-red portion of the spectrum. (If you see a "neon" light that isn't orange-red, it's probably not really using neon gas.)

A fluorescent light is exactly the same, except that the inside of the tube is coated with a fluorescent material. It absorbs the (high frequency) energy emitted by the gas discharge itself, and emits energy at a lower frequency (characteristic of the specific material). The gas in fluorescent lights is usually low-pressure Mercury vapor, whose dominant emisison frequencies are in the ultraviolet. This is absorbed by the phosphor in the tube and re-emitted as a lower frequency (in the visible spectrum). Most fluorescent lights have a mixture of phosphors so that the emitted light appears "white" because it's actually a mix of different colors that kind of "average out" to white (this is like how the red, green, and blue phosphors in a CRT "blend" to appear white).

To confuse matters even further, a lot of modern "neon" lights are actually just fluorescent lights with a colored dye or sleeve applied to the tube (if the tube, when off, appears white, colored, or "cloudy", it's probably a fluorescent light instead; if it's clear and looks empty, then it's pure gas-discharge). This allows for the production of "neon" lights of any color desired and also allows different sections of the tube to have different colors.

An incandescent light glows because it's hot ("black body" radiation or "cavity" radiation). There's no characteristic frequency, though there is an emissions maximum which varies depending on temperature. If it's relatively cool ("red hot" is relatively cool as used here), it will appear a dull red; as it gets hotter it turns bright red, then orange, then yellow, then white, and ultimately starts to appear to have a bluish tinge as the emissions maximum shifts to shorter and shorter wavelengths.