It can be described as a constant variation
Answer:
The number of atoms is 
Explanation:
From the question we are told that
The mass of coin is 
Number of atom in one mole = 
Molar mass of nickel 
Now the relation to obtain the number of atom in the nickel coin is



Answer:
When scientists have a question, they form a hypothesis, <em>which</em><em> </em><em>is</em><em> </em><em>an</em><em> </em><em>idea</em><em> </em><em>that</em><em> </em><em>may</em><em> </em><em>be</em><em> </em><em>proved</em><em> </em><em>or</em><em> </em><em>disproved</em><em> </em><em>by</em><em> </em><em>an</em><em> </em><em>experiment</em><em>.</em>
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.