Which of the following series of isoelectronic ions (Mg²⁺, N³⁻, F⁻, Si⁴⁺) has the ionic radii in order of largest to smallest? A) Mg²⁺ > N³⁻ > F⁻ > Si⁴⁺ B) Mg²⁺ > Si⁴⁺ > F⁻ > N³⁻ C) N³⁻ > F⁻ > Si⁴⁺ > Mg²⁺ D) N³⁻ > F⁻ > Mg²⁺ > Si⁴⁺ E) F⁻ > N³⁻ > Si⁴⁺ > Mg²⁺

If a 60-g object has a volume of 30 cm3, what is its density? 2 g/cm3 0.5 cm3/g 1800 g * cm3 none of the above

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.

Neils bohr believed that electrons orbited the nucleus in different energy levels, based on strong support from