The answer is 4.0075 x 10^9
intensity of a star is inversely depends on the square of the distance from the star
we can say it is given as

here we know that

also we know that

now we will have



so other star is at distance 60 Light years
<span>The waves with the lowest energy and lowest frequencies of the electromagnetic spectrum are the "Radio waves"
So, option B is your answer
Hope this helps!
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Well let’s put it this way. To find the neutrons you subtract the atomic atomic Nuremberg from the atomic mass. So
Mass=81-Number=28
81-28=53
Final answer is 53.