Which compound is known as night glowing pigment from below?
- ACopper Sulphide doped zinc oxide
- BEuropium doped strontium aluminate
- CBarium sulphate doped copper carbonate
- DBoron oxide doped copper sulphate
Show answer and explanation
Correct answer: (b) Europium doped strontium aluminate
Explanation
Night-glowing pigments are phosphorescent materials that absorb UV light and re-emit it slowly in the dark.
Strontium aluminate (SrAl₂O₄) doped with europium (and dysprosium) gives high brightness, long afterglow up to 12 hours, and is non-toxic.
Copper-sulphide-doped zinc oxide and the other options lack this efficient, long-lasting glow.