Importance Of Chemistry

Step 1: Polymethyl methacrylate (PMMA) is commonly used in optical lenses due to its transparency and high refractive index. It is also known as acrylic or acrylic glass.
Step 2: PMMA is preferred for optical applications because of its clarity, durability, and ease of molding into precise shapes.
Step 3: Other polymers like polypropylene, polyvinyl chloride, and polythene are not as suitable for optical lenses due to their lower transparency and optical properties.

Step 1: Understanding oxidation states in actinoids.
- Actinoids exhibit variable oxidation states due to the involvement of and orbitals in bonding.
- The energy difference between these orbitals is small, allowing easy promotion of electrons to higher energy states.
Step 2: Comparing actinoids with lanthanoids.
- In lanthanoids, electrons are more strongly bound, leading to fewer oxidation states.
- In actinoids, the electrons are more delocalized, leading to a wider range of oxidation states.