<span>Ni = 5
The Rydberg formula for hydrogen is
1/w = R(1/a^2 - 1/b^2)
where
w = wavelength in vacuum
R = Rydberg constant 1.0973731568508x10^7 1/m
a,b = integers greater than or equal to 1 and a < b
Now we need to select the value for a.
a = 1 will converge towards 91.13 nm
a = 2 converges towards 364.51 nm
a = 3 converges towards 820.14 nm
...
Because of this, we will assume a = 1 for this problem since it converges closest to the wavelength given.
Substitute known values
1/w = R(1/a^2 - 1/b^2)
1/9.504x10^-8 = 1.0973731568508x10^7(1/1^2 - 1/b^2)
10521885.52 = 1.0973731568508x10^7(1/1 - 1/b^2)
0.958824759 = 1 - 1/b^2
-0.041175241 = -1/b^2
0.041175241 = 1/b^2
24.28643927 = b^2
4.928127359 = b
So Ni = 5.</span>
        
             
        
        
        
Answer:
21.81grams
Explanation:
According to the question, an agar medium requires the following ingredients: 21 grams (g) of
agar, 500 mg of dextrose, 3 dg of sodium, and 1 cg of potassium per 1,000 milliliters (mL) of distilled water.
Hence, the dry ingredient contain 21grams (g) of agar, 500milligrams (mg) of dextrose, 3decigrams (dg) of Sodium, and 1centigrams (cg) of pottasium. 
We need to convert all units (not in grams (g)) to grams. 
1grams = 1000milligrams
500 milligrams = 500/1000
= 0.500grams.
1grams = 10decigrams
3decigrams = 3/10
= 0.3grams
1grams = 100centigrams
1centigrams = 1/100
= 0.01 grams
Therefore, we have 21g, 0.500g, 0.3g, and 0.01g
The total dry weight of the ingredients will be:
21 + 0.500 + 0.3 + 0.01
= 21.81grams