During which era did plants first appear on an island ?
a. cenozoicb. mesozoic
c. paleozoicd. precambrian

Complete the sentence. the lower the hydrogen ion concentration, the the ph. higher lower closer to 7 closer to 0

Select the correct answer. when carbon dioxide dissolves in water, it sometimes reacts with water to form carbonic acid as in this balanced equation: co2 + h2o → h2co3. if 495 milliliters of carbon dioxide at 25°c and 101.3 kilopascals reacts with excess water, what is the theoretical yield of carbonic acid? use the periodic table and the ideal gas resource a. 0.889 g b. 1.10g c. 1.27g d. 2.02g what's the answer! quick!

What is the formula for the compound dinitrogen pentoxide? a. n4o5 b. n5o4 c. n4o6 d. n5o2 e. n2o5