Which particle diagram represents a mixture

Si una estrella no tiene paralaje medible, ¿qué puedes inferir?

What is the mass defect of a mole of nuclei with 1.8 x 10^15 j/mol binding energy?

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.