in a petri dish, a certain type of bacterium doubles in number every 30 minutes. there were originally 16, or 2^4, bacteria in the dish. after 150 minutes, the number of bacteria has doubled 7 times, multiplying by 2^7. Now the population of bacteria is 2^4 • 2^7. Expressed as a power, how many bacteria are in the petri dish after 150 minutes? A. 2^28 B. 2^11 C.4^11 D.2^7

Which of the following elements is a representative element? a. chromium (cr) b. aluminum (al) c. mercury (hg) d. silver (ag)

What are the percent by mass of copper in penny lab

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.