Serum taken from a patient being treated with lithium for
manic-depressive illness was analyzed for lithium concentration. a
reading of 212 units was obtained for the intensity of the 671 nm
red emission line. then 1.00 ml of a 11.2 mm lithium standard was
added to 9.00 ml of serum, and this spiked serum gave an intensity
reading of 546 units. what is the original concentration of li in
the serum?

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation:

put the answers   and i could answer.

let that person have a turn to speak : )

i think   the answer is c hope i'm right