At 4 °C, the clusters start forming. The molecules are still slowing down and coming closer together, but the formation of clusters makes the molecules be further apart. Thus, the density of water is a maximum at 4 °C.
Gamma rays because the kill every living cell and they have the shortest waves that are dangerous
I'm not sure but i would say C.storing the heat energy.
<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
PH + pOH = 14
12.52 + pOH = 14
pOH = 14 - 12.52
pOH = 1.48
[OH⁻] = 10^ -pOH
[OH⁻] = 10 ^- 1.48
[OH⁻] = 0.033 M