Water has a specific heat of 4.186 j/g°c, and ethanol has a specific heat of 2.450 j/g°c. based on this information, which best compares water and ethanol?
it requires more heat to raise the temperature of a gram of ethanol by 1°c.
there are more molecules in a gram of water.
ethanol has a lower formula mass.
water has more protons and neutrons in its nuclei.

There are more molecules in a gram of water.

Explanation: Specific heat is the heat required by 1 gram of a substance to raise its temperature by .

As the specific heat of water (4.186 J/g°C) is more than that of ethanol (2.450 J/g°C) it means more energy is required to raise the temperature of a gram of water by 1°C. Which means the molecules are tightly bound and thus more molecules are contained in a gram of water.

Q= heat gained

m= mass of the substance

c = heat capacity    

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia