It takes 33.4 s for the concentration of A to fall to one-fourth of its original value.
A <em>half-life</em> is the time it takes for the concentration to fall to half its original value.
Assume the initial concentration is 1.00 mol/L. Then,

The concentration drops to one-fourth of its initial value in two half-lives.
∴ Time = 2 × 16.7 s = 33.4 s
my answer is D sorry if I'm wrong
A: incorrect because there will be no effect on keeping the rats in separate cage in the same room at the time of the experiment.
C: incorrect because it's depend upon scientist whether he wants to record the observation on the graph or on the table. Thus, no affect will be caused on the observations.
D: incorrect because peer review is done only after the experiment is completed.
Thus, statement B is correct because the growth graph of male and female of any species is different. Male tend to grow more than their female counterparts. So, for the process of the study it is essential that all the rats included are either male or female.
Hence, option (B) is correct.
No it is an amino acid present in the synthesis of certain proteins. Elements are pure substances so an acid (which is a compound of different elements) would not be considered an element.
Gilbert N. Lewis (1875-1946) was an American physical chemist.
His work with heavy water and resources were adapted by Ernest Lawrence in the development of the cyclotron.
SCIENTIFIC CONTRIBUTIONS
Lewis made many contributions to science. He was nominated for the Nobel Prize 41 times, though he was never awarded the prize.
He discovered covalent bonds and electron pairs. He worked with isotope separation, and became the first person to purify a sample of heavy water. The heavy water was later used as projectiles in Lawrence’s 27-inch cyclotron.
He also made contributions in ideas on relativity and acid-base reactions and coined the term “photon” as the smallest unit of light.