Certain byproduct in nuclear reactors, 210po, decays to become 206pb. after a time period of about 276 days, only about 25% of an original sample of 210po remains. the remainder has decayed to 206pb. determine the approximate half-life of 210po.

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as

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.

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false