Did You Know? 1. What is the hardest material on Earth? Answer: Diamond is the hardest material, with a score of 10 on the Mohs scale of mineral hardness. 2. What is the lightest metal on Earth? Answer: Lithium is the lightest metal, making it a popular choice for aerospace applications. 3. Which material is known for its superconductivity at low temperatures? Answer: Niobium is a superconductor that is commonly used in industries such as medical imaging and particle accelerators. 4. What is the most abundant element in the Earth's crust? Answer: Oxygen makes up about 46% of the Earth's crust, followed by silicon. 5. What material is widely used in optical lenses due to its transparency and durability? Answer: Glass is a versatile material that is essential for various optical applications. 6. What is the main element in steel that gives it its strength? Answer: Iron is the primary element in steel, which is alloyed with carbon to enhance its strength and durability. 7. What is the process of heating and cooling a material to change its properties? Answer: Heat treatment is a common process used in material science to alter the structure and properties of a material. 8. Which element is added to aluminum to make it stronger? Answer: Copper is often added to aluminum to create a stronger alloy for applications that require high strength-to-weight ratio.