Isot pe Practice Here are 3 isotopes of an Element: "2c sc 1ac a. b. نه نه ن و ه ی The name of the element is: The number 6 refers to the: The numbers 12,13, and 14 refer to the: How many Protons and Neutrons are in the first isotope? How many Protons and Neutrons are in the second isotope? How many Protons and Neutrons are in the third isotope? d. e. Isotope Name Atomic Mass # of Protons Atomic Number # of Neutrons # of Electrons 92 92 uranium-235 92 146 92 uranium-238 10. 5 boron-10 5 5 boron-11

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.