Consider the following statements: Statement I: Some rare earth elements are used in the manufacture of flat television, screens and computer monitors, Statement II: Some rare earth elements have phosphorescent properties. Which one of the following is correct in respect of the above statements?

1. A. Both Statement I and Statement II are correct and Statement II explains Statement I
2. B. Both Statement I and Statement II are correct but Statement II does not explain Statement I
3. C. Statement I is correct but Statement II is not correct
4. D. Statement I is not correct but Statement II is correct

Answer: A

Explanation

Statement I is correct. Rare Earth Elements (REEs) like europium, terbium, and yttrium are indeed crucial components in the manufacture of flat-panel displays, including televisions, screens, and computer monitors. They are used in phosphors to produce the vibrant colors seen on these screens. Statement II is correct. Many rare earth elements possess phosphorescent (or luminescent) properties, meaning they can emit light when excited by energy. This characteristic is precisely why they are used in displays. When electrons or UV light excite the REE compounds, they emit light in specific colors, which is essential for creating the red, green, and blue pixels in screens. Therefore, Statement II correctly explains why rare earth elements are used in displays as mentioned in Statement I. The strategic importance and unique properties of REEs are significant for UPSC Science & Technology and Economy.