Which of the following gases emits red light when electricity is passed through it?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. Neon.
The gas that emits red light when electricity is passed through it is neon. Neon gas is commonly used in neon signs, where an electrical discharge excites the neon atoms, causing them to emit light. The characteristic red glow is a result of the specific energy transitions of neon atoms. Neon lights can be produced in various colours, but red is the most common and prominent, as neon emits light primarily in the red and orange spectrum when energized.