Answer : The wavelength of photon is, 
Explanation : Given,
Energy of photon = 
Formula used :

As, 
So, 
where,
= frequency of photon
h = Planck's constant = 
= wavelength of photon = ?
c = speed of light = 
Now put all the given values in the above formula, we get:


Conversion used : 
Therefore, the wavelength of photon is, 
Ca(NO3)2(aq) + Na2CO3(aq) → 2NaNO3 + CaCO3⬇. NaNO3 is solution so CaCO3 is the precipitate formed.
It’s because flourecent lights operate at higher temperatures than incadecent lights.
Answer:
John Dalton
Explanation:
Dalton's atomic theory was the foundation for a new understanding of chemical structures. He proposed that matter was constituted by indivisible and indestructible particles "atoms." He theorized that all atoms of a particular substance were equal, and the atoms of different substances had atoms of different sizes and masses.
He also proposed that all compounds of elements were combinations of elements but in a very precise ratio.
Answer:
c.) sewage and industrial waste