Which describes a chemical property of silicon? (1) silicon has a blue-gray color
(2) silicon is a brittle solid at 20oc
(3) silicon melts at 1414oc
(4) silicon reacts with fluorine

Blank allows you to do calculations for situations in which only the amount of gas is constant a)boyle's law b)combined gas law c)ideal gas law d)dalton's law

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.

What energy is it when you flip on a switch on a lamp