What were the first living organisms on earth and how did they change earth's development and composition?

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?

Consider the heating curve of h2o and line segments a, b, and c. several changes are taking place at a, b, and c. all but one would be an appropriate description as e move through segments a, b and then c.