Witch event signals the birth of a star

Nitrogen (n), phosphorus (p), and potassium (k) are the main nutrients in plant fertilizers. according to an industry convention, the numbers on the label refer to the mass percents of n, p2o5, and k2o, in that order. calculate the n: p: k ratio of a 30: 10: 10 fertilizer in terms of moles of each element, and express it as x: y: 1.0.

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

Which of the following are correct values for the ideal gas laws constant r