Uranium provides nuclear fuel used generate electricity in nuclear power station,also used by the military to power nuclear submarines and in nuclear weapons.
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:
78.14 % B; 21.86 % H
Step-by-step explanation:
The formula of diborane is B₂H₆.
The masses of each element are:
2B = 2 × 10.81 = 21.62 u
6H = 6 × 1.008 = <u> 6.048 u
</u>
TOTAL = 27.67 u
% B = 21.62/27.67 × 100
= 78.14 %
% H = 6.048/ 27.67
= 21.86 %