In the US Alternating Current is used. It has a frequency of 60 Hz. If you are looking at the waveform for AC how many wavelengths pass in 2 seconds? A.24
B.240
C.60
D.120

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

Elements that do not have full outer electron shells will donate, share, or take electrons from other atoms. choose the items that have the correct binary ionic formula.

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.