Which best describes the purpose of a controlled expierment

Why do scientists look for patterns in the world? a. patterns can explain observations. b. patterns never change, no matter what. c. patterns are easy for scientists to detect. d. patterns are all the same, through all time.

32p and 31p are two isotopes of phosphorus. compare the number if subatomic particles that are present in the atoms of these isotopes.

Be sure to answer all parts. the catalytic destruction of ozone occurs via a two-step mechanism, where x can be any of several species: (1) x + o3 → xo + o2 [slow] (2) xo + o → x + o2 [fast] (a) write the overall reaction. o3 + o → 2 o2 o3 + xo → x + 2 o2 xo + x + o3 + o → xo + x + 2 o2 x + o3 → xo + o2 (b) write the rate law for each step (using k for the rate constant). reaction 1: reaction 2: k[x][o2] k[xo][o2] k[x][o3] k[xo][o3] k[xo][o2] k[x][o] k[x][o2] k[xo][o] (c) x acts as a and xo acts as a catalyst intermediate intermediate catalyst (d) high-flying aircraft release no into the stratosphere, which catalyzes this process. when o3 and no concentrations are 3 ă— 1012 molecule/cm3 and 9.9 ă— 109 molecule/cm3, respectively, what is the rate of o3 depletion? the rate constant k for the rate-determining step is 6 ă— 10â’15 (cm3)2/moleculeâ·s. give your answer in scientific notation. use one significant figure in your answer. ă— 10 molecule/s