The atmosphere is the air surrounding Earth and is made up of 78% , 21% oxygen, and other trace gases. Please help this is urgent!!

Which of the following describes a situation where competition between producers exists

Rank the following four acids in order of increasing bronsted acidity : h2f+ , ch3oh, (ch3)2oh+ , ch3sh2+

Calculate the ph at the equivalence point for the titration of a solution containing 150.0 mg of ethylamine (c2h5nh2) with 0.1000 m hcl solution. the volume of the solution at the equivalence point is 250.0 ml. kb forethylamine is 4.7 × 10−4 .