Electronegativity values are useful in determining if a bond is to be classified as nonpolar covalent, polar covalent or ionic. Consider the following chemical compounds. Which compound exhibits polar covalent bonds and why? A) NaCl; ionic bond EN = 2.1

B) SO; polar covalent EN = 1

C) CH; non-polar covalent EN = .04

D) H2; polar covalent EN = 0

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.

Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with this sample so that the rate of neutron production drops down to 1.8 neutrons per fission event, which will be effective at achieving a critical mass? check all that apply. remove a deflective shield surrounding the sample. remove absorbent material mixed in with the sample. compress the sample of americium-241.

Carbon-14 undergoes radioactive decay in the reaction above. determine the type of radiation emitted in this reaction and describe what is happening to the nucleus during this reaction.