Q1: The following is employed as sacrificial anode to provide cathodic protection to ships, pipelines and storage tanks.

ANS:D - Magnesium

Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a silvery-white, lightweight metal that is highly reactive. Here's an explanation of magnesium and its properties:

1. Physical Properties:
   • Lightweight: Magnesium is one of the lightest structural metals, making it ideal for applications where weight reduction is critical, such as in aerospace and automotive industries.
   • Malleable and Ductile: Magnesium is malleable and ductile, meaning it can be easily shaped and formed into various structures and components.
2. Chemical Properties:
   • Reactivity: Magnesium is highly reactive, especially with oxygen, water, and acids. It readily forms compounds such as magnesium oxide (MgO) and magnesium hydroxide (Mg(OH)2).
   • Corrosion Resistance: While magnesium itself is prone to corrosion in certain environments, its alloys can be engineered to exhibit improved corrosion resistance.
3. Applications:
   • Aerospace Industry: Magnesium and its alloys are used extensively in aerospace applications due to their lightweight properties. They are used in aircraft fuselages, wings, landing gear, and other structural components to reduce weight and improve fuel efficiency.
   • Automotive Industry: Magnesium alloys are used in automotive parts such as engine blocks, transmission cases, steering wheels, and structural components. Again, the lightweight nature of magnesium contributes to fuel efficiency and vehicle performance.
   • Electronics: Magnesium is used in electronics and consumer goods such as laptops, cameras, and mobile phones due to its lightweight and machinability.
   • Medical Applications: Magnesium alloys are used in medical implants and devices due to their biocompatibility and ability to degrade in the body over time.
   • Cathodic Protection: Magnesium is employed as sacrificial anodes in cathodic protection systems to prevent corrosion in structures such as ships, pipelines, and storage tanks. In these systems, the magnesium anode corrodes sacrificially to protect the underlying metal structure.
4. Health Benefits: Magnesium is an essential mineral for human health and is involved in various biological processes, including muscle and nerve function, energy production, and bone health. It is found in foods such as nuts, seeds, whole grains, and leafy green vegetables.