Answer:

Explanation:
It is given that,
The number of lines per unit length, N = 900 slits per cm
Distance between the formed pattern and the grating, l = 2.3 m
n the first-order spectrum, maxima for two different wavelengths are separated on the screen by 2.98 mm, 
Let d is the slit width of the grating,



For the first wavelength, the position of maxima is given by :

For the other wavelength, the position of maxima is given by :

So,



or

So, the difference between these wavelengths is 14.3 nm. Hence, this is the required solution.
Answer:
The Apollo program or Project Apollo was a series of human spaceflight missions undertaken by the u.S. Devoted to the goal of landing a man on the moon and returning him to earth safely.
Explanation:
Project Apollo or Apollo program was the spaceflight program carried out by the United States of America during the years 1961-1972 using the Apollo spacecraft. This project's main goal was to land a man on the Moon and to safely return him to Earth. This goal was accomplished with the Apollo 11 moon-landing mission on July 20, 1969, when an Apollo Lunar Module (LM) landed on the Moon's surface and the astronauts Neil Armstrong and Buzz Aldrin walked on the lunar surface while Michael Collins stayed in the command and service module (CSM) in the lunar orbit. On July 24, all three astronauts landed safely on Earth.
This project included three unmanned test flights (Apollo 4 through Apollo 6) and eleven manned flights (Apollo 7 through Apollo 17). All these spaceflight missions were carried out by NASA (National Aeronautics and Space Administration) and all were launched from the Kennedy Space Center, Florida.
If something was turned? I'm not really sure what you are talking about, but for something to become a chemical reaction it involves and arrangement of molecular and ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction.
The answer is deposition/A. Please mark brainliest.