The answer is c electrostatic repulsion between nuclei
<u>Answer:</u> The wavelength of spectral line is 656 nm
<u>Explanation:</u>
To calculate the wavelength of light, we use Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 
= Final energy level = 2
= Initial energy level = 3
Putting the values in above equation, we get:

Converting this into nanometers, we use the conversion factor:

So, 
Hence, the wavelength of spectral line is 656 nm
Answer:
Q = 10.8 KJ
Explanation:
Given data:
Mass of Al= 100g
Initial temperature = 30°C
Final temperature = 150°C
Heat required = ?
Solution:
Specific heat of Al = 0.90 j/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 150°C - 30°C
ΔT = 120°C
Q = 100g×0.90 J/g.°C× 120°C
Q = 10800 J (10800j×1KJ/1000 j)
Q = 10.8 KJ
Answer:
I believe this is called the 'molar mass'
Blue litmus paper turning red means that the solution where the litmus paper was submerged is an acidic solution with a pH of less than 7. Another verification of the nature of the solution is the turning to red of methyl orange in acidic solutions. The answer then is D.