A city's water supply is contaminated with a toxin at a concentration of 0. 63 mg/l. For the water to be safe for drinking, the concentration of this toxin must be below 1. 5 x 10-3 mg/l. Fortunately, this toxin decomposes to a safe mixture of products by first-order kinetics with a rate constant of 0. 27 day–1. How long will it take for the water to be safe to drink?.

In which text sample are the ideas organized most logically? a. a butterfly starts its life as an egg. the egg hatches to reveal a tiny caterpillar. the caterpillar eats a lot of leaves. it grows quickly, shedding its skin as it grows. this shedding takes place four or more times in a process known as molting. the caterpillar then forms a pupa or chrysalis. inside the chrysalis, the caterpillar slowly transforms into a beautiful butterfly. b. the molting process is characteristic of caterpillars. eventually the caterpillar grows into a beautiful butterfly. the caterpillar eats a lot of leaves, growing quickly. as a result, it becomes too big for its skin, and it has to shed its skin four or more times. the caterpillar hatches from the egg laid by a butterfly. c. a tiny caterpillar hatches from the egg. the egg is the starting point of a butterfly’s life. when it becomes a caterpillar, it eats a lot of leaves. it grows quickly, shedding its skin as it grows. this shedding takes place four or more times. this process is known as molting. the caterpillar then forms a pupa or chrysalis. then the caterpillar slowly transforms into a beautiful butterfly. d. the caterpillar forms a pupa or chrysalis. inside the chrysalis, the caterpillar slowly transforms into a beautiful butterfly. but where does the caterpillar appear from? a caterpillar hatches from an egg. the egg is the starting point of a butterfly’s life. when it becomes a caterpillar, it eats a lot of leaves. it grows quickly, shedding its skin as it grows. this shedding takes place four or more times in a process known as molting.