Answer:
D
Explanation:
The inner core (which is solid) is the hottest layer of the earth. It, therefore, contributes to heating up the outer core. The outer core is liquid and rotation of the earth (Coriolis effect) causes the molten rocks to swirl like a tornado. Because the outer core is mostly made of metals, that have lost electrons and hence charged (due to the enormous heat), the swilring effect causing an electric effect. This consequently causes the dynamo effect that creates a magnetic field. This magnetic field covers the earth and protects it from harmful radiation from the solar storms.
Answer:
Solvent is 1.00 liter of water.
Answer: The vapor pressure of methanol solution at 298K is 107.12 torr
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,

where,
= relative lowering in vapor pressure
i = Van'T Hoff factor = 1 (for non electrolytes)
= mole fraction of solute =
Given : 38.5 g of urea is present in 142 g of methanol
moles of solute (urea) = 
moles of solvent (methanol) = 
Total moles = moles of solute + moles of solvent = 0.64 + 4.4 = 5.04
= mole fraction of solute =


Thus the vapor pressure of methanol solution at 298K is 107.12 torr
Answer:
Regularly test the water in residents' homes.
Explanation:
The only way to know if tap water contains lead is to do tests to determine the levels of that metal in the water. Therefore, the state is under an obligation to constantly conduct such tests in the resident´s homes and thus determine whether the water supplied is fit for human consumption.
The state after the tests must guarantee the population the treatment of the water to reduce the levels of lead. The main pipes that contain lead pipes must be changed, as well as those parts of the service connections made of lead.