Which is the next logical step in balancing the given equation?
n2 + o2 → no2

a. place the coefficient 2 in front of oxygen and nitrogen dioxide.
b. place the coefficient 3 in front of oxygen and nitrogen dioxide.
c. the equation is already balanced.
d. change the subscript of the nitrogen molecule to 1.

Jenny places a strip of ph paper into a solution. when she removes the ph paper, it has turned yellow-green. what should jenny do next to determine the ph of her solution? a. use a different testing method because the ph paper should not change colors b. place the ph paper into a machine that reads the ph of the solution c. compare the ph paper's color with the color of ph paper from another solution d. compare the ph paper's color with a chart of colors and ph ranges