If a substance has a half-life of 150 million years, what fraction of the atoms remain after 300 million years?
A. 1/8
B. 1/2
C. 1/4
D. 1/16

For the reaction c6h14(g) & longrightarrow; c6h6(g) + 4h2(g), δp(h2)/δt was found to be 2.5 x 10-2 atm/s, where δp(h2) is the change in pressure of hydrogen. determine δp(c6h14)/δt for this reaction at the same time.