What atom matches this electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰?

The drawing represents the movement of particles in a substance. what changes of state can this substance undergo

How does concentration affect reaction rate

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.