Question

exl #1: see si did you know that this neon sign is experiencing a change of state? when a neon sign lights up, like the one you see here, something is happening to the neon atoms inside the tube. how is this colorful sign related to kinetic energy and phase change? a the electrical current in the tube generates the neon gas that glows in the dark. b electrical energy excites the neon atoms. they spin faster in the tube producing electromagnetic waves that we see as colors. c neon atoms accelerate once electrical energy is turned on to the tube. the faster the atoms move in the tube, the brighter the glow we see. d electrical energy accelerates the electrons in the neon gas. the gas ionizes and becomes plasma, containing both positive and negative ions.

Explanation:

To determine the correct option, we analyze each choice:

• Option A: States that the electrical current generates the neon gas, which is incorrect as neon gas is already in the tube.
• Option B: Claims that neon atoms spin faster to produce electromagnetic waves, but the glow in neon signs is due to electron transitions, not atomic spin.
• Option C: Says neon atoms accelerate with electrical energy, but the key process is electron excitation and ionization, not atomic acceleration for brightness.
• Option D: Correctly explains that electrical energy accelerates electrons, causing the neon gas to ionize into plasma (a phase change) and emit light, aligning with the physics of neon signs (electron excitation, ionization, and plasma formation).

Answer:

D. Electrical energy accelerates the electrons in the neon gas. The gas ionizes and becomes plasma, containing both positive and negative ions.