Answer:
1.25 hours or 75 minutes or 1 hour and 15 minutes
Explanation:
(1) False, lots of energy is actually produced from nuclear fuel, if we didn't get much then we probably wouldn't use it
(2) False, its burning coal that contributes to acid rain, since it contains sulfur
(3) False again, we can control the reaction with aptly named control rods, which are typically made of boron, to absorb some of the neutrons flying around in the chain reaction
(4) True, radioactive waste is very difficult to dispose of, and is also very dangerous. Sources of radiation can remain so for millions of years
Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :

where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of a substance is 157.3 g/mol
The shape of the molecule will determine the direction of each of the individual bond dipoles, and thus, will always play a role in determining the polarity of the molecule as a whole.