Answer:
(B) II, IV.
hope this answer is helpful for u.
The equation that relates both energy and wavelength is:

where e is the energy and lambda is the wavelength.
Therefore, as we can see from this equation, the energy of an electromagnetic wave is inversely related to the wavelength of the electromagnetic wave.
Answer:

Explanation:
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In this case, since the normal boiling point of X is 117.80 °C, the boiling point elevation constant is 1.48 °C*kg*mol⁻¹, the mass of X is 100 g and the boiling point of the mixture of X and KBr boils at 119.3 °C, we can use the following formula:

Whereas the Van't Hoff factor of KBr is 2 as it dissociates into potassium cations and bromide ions; it means that we can compute the molality of the solution:

Next, given the mass of solventin kg (0.1 kg from 100 g), we compute the moles KBr:

Finally, considering the molar mass of KBr (119 g/mol) we compute the mass that was dissolved:

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Answer:
18857
Explanation:
1j=0.239cal
78.9kj=78900j
78.9kj= 78900×0.239=18857cal