Which of the following sets are isoelectronic (i. e., have the same number of electrons)? i. Br-, Kr, Sr2+ ii. C, N-, O2- iii. Mg2+, Ca2+, Sr2+ iv. O2-, O, O2+ v. Ag+, Cd2+, Pd

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.

Which reason best explains why metals are malleable? a)because they have delocalized electrons b)because they have localized electrons c)because they have ionic bonds d)because they have rigid bonds

Which of the following is true about the speed of light? it depends on the wavelength.