Both statements are correct, and Statement II explains Statement I. Rare earth elements are indeed used in TV and monitor screens, primarily due to their phosphorescent properties. These elements, such as europium and terbium, are used in phosphor materials that emit specific wavelengths of light, which is crucial for the color displays in television screens and computer monitors. The phosphorescent properties of rare earth elements enable them to emit light when exposed to energy sources, making them essential for vibrant and high-resolution displays.