Which of the following involves a chemical reaction? evaporation

combustion

condensation

dissolution

H2so4(aq) + mg(s)—> mgso4(aq) +h2(g) which substance is the acid in the reaction?

Often on a topographic map, every fifth contour line is darkened. what is this line called? a. key b.slope c.benchmark d. index contour

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.