When silicon is oxidized, some silicon is consumed from the surface to form silicon dioxide. The Pilling-Bedworth (P-B) ratio is the ratio of SiO2 volume grown to Si volume consumed. Required:
a. Derive an equation for calculating the P-B ratio in terms of Si and SiO2 molecular weights and densities.
b. Draw to scale cross-sections of a silicon wafer before and after growing 1000A of SiO2. Align the drawings using the original Si surface as a reference. Label the diagram completely, including the original surface, the oxide surface, and the Si-SiO2 interface.

How many atoms of mg are present in 97.22 grams of mg? 6.022 × 1023 2.408 × 1024 4.818 × 1024 5.855 × 1025

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.

Which of these features are formed when hot groundwater is forced out through cracks in the earth's surface?