Answer:
:)
Explanation:
If we subtract the atomic number from the atomic mass: atomic mass - atomic number = number of protons + number of neutrons - number of protons. Thus we get the number of neutrons present in an atom when we subtract the atomic number from the atomic mass.
The vise president of India is M. Venkaiah Naidu
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.
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