The fraction of a radioactive isotope remaining at time t is (1/2)^t/t1/2 where t1/2 is the half-life. if the half-life of carbon−14 is 5,730 yr, what fraction of carbon−14 in a piece of charcoal remains after
(a) 14.0 yr?
(b) 1.900 × 10^4 yr? × 10 (enter your answer in scientific notation.)
(c) 1. × 10^5 yr? × 10 (enter your answer in scientific notation.)

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н,о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.

How have the greenhouse gasses increased from the year 2000 to 2018

Tell me the iupac names of the following alcohols: