First i wanted to say you look preety LOL
1) Determine the rate constant for the reaction:
<span>k = (ln 2) / t_1/2 <--- I'll leave you to figure out how that came to be. Hint: use the integrate form of the first-order rate law </span>
<span>k = (ln 2) / 23.6 min </span>
<span>k = 0.02937 min^-1 <--- keep a few extra digits </span>
<span>1) use the integrated form of the first-order rate law: </span>
<span>ln A = -kt + ln A_o </span>
<span>ln A = - (0.02937 min^-1) (120 min) + ln 2.50 </span>
<span>ln A = -3.5244 + 0.91629 </span>
<span>ln A = -2.60811 </span>
<span>A = 0.07367 M <--- round off more as you see fit </span>
<span>Here's another way: </span>
<span>120 min / 23.6 min = 5.106383 half-lives </span>
<span>(0.5)^5.106383 = 0.02902856 <--- the decimal amount remaining after 5.106383 half-lives </span>
<span>0.02902856 x 2.50 M = the answer</span>
Answer: 12 neutrons
Explanation: The mass number of an element tells us the number of protons AND neutrons in an atom (the two particles that have a measurable mass). Sodium has a mass number of 23amu. Since sodium has 11 protons, the number of neutrons must be 23 – 11 = 12 neutrons.
The volume will decrease, because as the temperature is lowered, the atoms will move slowler and they won't fill as much the balloon