In which numbered position would a Period 4 element that is a metal with three valence electrons be located?

Why does asexual reproduction result in offspring with identicle genetic variation

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.

The plant food contains nh4)3po4 what tests would you run to verify the presence of the nh4 ion and the po4 ion