Answer:
1. Weight.
2. Large lens will tend to deflect under its own weight
Explanation:
Hello,
Weight is a big part of it. There’s a reason the largest working refractor on Earth (the Clark refractor at Yerkes Observatory in Wisconsin) has a 102-cm objective; a 125-cm lens was created for the Paris Exposition of 1900, but the accompanying telescope was a pain to use (very hard to aim) and was scrapped when no one wanted to buy it.
Lens can only be supported at its edges unlike mirrors, and a large lens will tend to deflect under its own weight unless it’s so thick that it won’t transmit much light. It is also extremely difficult to cast and polish a glass blank of such huge size, which is why (see List of largest optical refracting telescopes - Wikipedia) almost no one has tried building one in over a century.
Best regards.
Explanation:
False, they also provide oxygen
4% of the mass of air. Hot air can hold more water vapor than cold air, so the amount of water vapor is highest in hot, tropical areas and lowest in cold, polar regions
Explanation:
Explanation:
The nitrate anion is a univalent (-1 charge) polyatomic ion composed of a single nitrogen atom ionically bound to three oxygen atoms (Symbol: NO3) for a total formula weight of 62.05. Lead Nitrate is generally immediately available in most volumes.
