What is ph?
a) the negative logariuthm of the hydrogen ion concentration
b) the positive logariuthm of the hydrogen ion concentration
c) the negative logarithm of the hydroxide ion concentration
d) the positive logarithm of the hydroxide ion concentration

Name the element in group 17, period 2. (periodic table)

Drug abuse will not lead to physical and psychological dependence. true or false ?

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.