The light intensity of a source is 100 candelas. the illuminance on a surface is 4 lux. how far is the surface from the source?

a. 7 meters
b. 6 meters
c. 4 meters
d. 5 meters

An observation that requires measurement is called quantitative observable or qualitative

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.

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.