If one half life is the amount of time it takes for a radio active isotope to decay by a factor of 2, approximately which percent describes how much of the initial quantity of a substance would remain after 2-3 half lives? A.0.25
B.0.20
C.0.75
D.0.50

The boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a) e = 2b - 212 b) b = 2e - 212 c) e = -2b + 212 d) b = -2e + 212