Do you think his evidence is strong? Why or why not?

No, the evidence is not strong enough, as there is a lack of repetition and information on how the experiment was done.

The first thing that is missing is information on how the experiment was done, things like

Strong and weak magnets behave in the same way, opposite poles attract and equal poles are repelled, thus, there must be a problem with Barry's experiment.

Ignoring that, another problem is the lack of repetitions. An experiment must be done several times to see if the results are always the same, in the given evidence it was done only once for each, so we don't know if after another trial the outcomes will be the same.

If you want to learn more about experiments, you can read:

link

No

Explanation:

The reason why Barry's evidence isn't strong because "it's not enough to support his claim" that strong magnets repel and weak magnets attract. Barry needs to have at least three trials for each test to greater prove his claim. Doing so will show that the test isn't incorrect because he repeated the test multiple times and got the same results. If Barry does three trials for each test and record his results then he would have enough evidence to support his claim.

Hope this helps.

i would think it's food chain

1/0.14nm = 10^10/1.4 a lot