How many moles are in 4.57 x 103 mg of Ca(NO3)2? A) 2.79 x 102 mol
B) 27.9 moles
C) 2.79 x 104 moles
D) 1.67 x 1022 moles
E) none of the above

Which of the following is an example of how telecommunication devices people do their jobs? a.) a security guard checks the time using a digital watch. b.) a banker does some quick math using a solar calculator. c.) a nurse uses a digital thermometer to take a patient’s temperature. d.) a construction worker reports in to his office using a cell phone.