In the chemical reaction below, sodium (na) and chlorine (cl) combine to form sodium chloride (nacl). 2na + cl2 → 2nacl if the combined mass of the starting reactants is 50 grams, then the mass of sodium chloride formed once the reaction has reached completion a. will be exactly 50 grams. b. will be exactly 100 grams. c. will be between 50 and 100 grams. d. will be less than 50 grams.

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