Ytterbium
Similar to other rare earth metals, Ytterbium has a bright silver luster, is soft, malleable and ductile, oxidizes when exposed to air and is often kept in closed containers. Its application is quite limited, but as an alloying component, Ytterbium can increase the strength of stainless steel. Ytterbium alloys are currently used in dentistry. In the future, Ytterbium may be used to make atomic clocks with greater precision in the future – the isotope Ytterbium174 is theoretically better than Caesium (Caesium clocks are already accurate to 1 second per 100 million years).