According to the u. s. environmental protection administration, the concentration of radon-222 in air in equilibrium with its short-lived daughters in a home at which remediation should be done is 4 pci/liter. this corresponds to how many atoms of radon-222 per cm? ? note: rn-222 half-life is given as 3.8 days.]

The higher the astm grain size number, the finer the gran is. a)-true b)-false

An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0

Vibration monitoring this technique uses the noise or vibration created by mechanical equipment and in seme cases by plant systems to detemine their actual condtion. a)- true b)- false