How to write a Physical Review-style paper:

1. First: you need to present (graph, plot, etc.) your data. You need to find two or three *data plots* that convey the meat of what you did in the lab. Spend time on these plots. I mention them first because they are, in a sense, the most important part of the paper. Simple things matter: Label your axes, including both meaning and, if necessary, units. ("razor position (mm)" or "spectral power density (W/Hz)" or "log counts/bin"). Consider both economy (can you overlay several data graphs on one set of axes and esthetics (does your dark-blue theory curve make it hard to see the black data points Plots do not have to be raw data---i.e. numbers straight from the lab notebook. They can be processed to remove meaningless constants, to change units, etc. For example, if I chose to plot a laser-beam-diameter measurement sequence, I'd probably shift the x-axis so that 0 represented the center of the laser. Before plotting data from a multichannel analyzer, go ahead and convert channel-number to a physics unit (energy, time, etc) using your calibration. And so on.
2. Your paper needs an *abstract*. The abstract must, in three or four terse sentences, summarize the paper so the reader knows whether to read the whole thing. Generally you get once sentence of motivation, one sentence describing your approach, and one sentence of results, including a key number or two. (Would another sentence make it much, much clearer Then add another sentence.)
3. Your paper needs professional-style *references*. You should cite two or three basic papers (in the 128 labs, the appropriate papers might well be from 1890-1910) as you introduce the *theory* of what you're doing. You might cite a paper or two justifying particular experimental details---it's fine to cite published equipment manuals, for example, or Taylor's data-analysis textbook. If you are aware of someone else's *experimental results*, compare their results to yours, and cite them. YOU MAY NOT CITE THE LAB MANUAL OR WIKIPEDIA. I bet that there is not one Wikipedia citation in the entire Physical Review journal series (except in articles treating Wikipedia itself as a topic for nonlinear systems analysis). And let's maintain the fiction that you've just done a novel experiment, on your own initiative, figuring out the details yourself, and that the lab manual does not exist. (You may, of course, *follow* citation-links to figure out where Wikipedians, lab-manual-authors, etc., got their information.)
4. Your paper needs well-written, appropriately-voiced text. To get a feel for this voice and writing style, go over to the ArXiV (preprints, some are terrible) or to Physical Review (Phys Rev Letters is the best place to start. For models for this paper, avoid Reviews of Modern Physics and Phys Rev D.) and scan some random artiles. Basics:
   • You need to outline the basic physics theory of what you're working with. (It doesn't need to be a full derivation. This is not a textbook, it's a paper. You certainly don't need to show algebra---"divide both sides of equation 1 by hbar to obtain equation 2 ...")
   • You need to explain the experiment---often a diagram will be helpful at this point. (You don't need to explain every detail---what knob you turn when, how you turn the laser on. This is not a lab manual.)
   • You need to explain, in words, the data analysis that led to your figures. ("We obtain the electron mass from 203 measurements. For each measurement, we record the accelerating voltage U and the time-of-flight t and calculate the mass. The typical error found from error propagation is 0.1%, in poor agreement with the scatter of 0.3% as seen in a histogram in figure 2")
   • You need to draw, explain, and justify a concrete conclusion. ("Therefore we conclude that the electron mass is 518 +/- 3.5 keV. This is in agreement with the value obtained by Millikan (ref 6) but disagrees by two standard deviations from the CODATA value of 510.998 keV. Possible explanations include ...")
5. All text and figures must be your own work. This is no longer a collaboration between you and your lab partners. You and your partners worked together to produce the data, and to analyze it, but this is your own individual presentation of that data---your introduction, your text, your references, YOUR diagram of the experimental setup, and (to whatever extent possible) I'd like your own tidied-up/labeled/organized plots. I take plagiarism very seriously and I adhere to the strictest definition of it. If you spend a moment wondering whether your particular copy-paste-and-paraphrase job fits my definition of plagiarism, then yes, it probably does.