Question

Which answer best explains why Mendeleev's periodic table became the first widely accepted organized scheme for the elements?

Mendeleev, as a Russian scientist, had a better scientific reputation at that time.

Mendeleev was born from a prominent family and therefore his work got more attention.

Mendeleev mounted a campaign to discredit all earlier versions because they had no validity.

Mendeleev's investigations suggested previous versions did not work for all known elements.

Answer 1

clearly the last option is correct

Answer 2

None of these. All these answers suggest the questioner doesn't understand how science actually works, and instead has some silly social-science beliefs about it. Particularly the strange references to Mendeleev's social status or reputation, which almost never matter in science.

What's important is that there was experimental evidence in many places that supported Mendeleev's ideas. That's what's key in science: a theory is never influential unless and until there is broad experimental evidence for it. Good scientists are never especially impressed because a theory is clever, or very logical, or hangs together well, or is beautiful. Any decent scientist -- really, almost any educated adult -- can explain any given small subset of facts about the world with ten beautiful and logical theories, which each contradict the other nine. Imagining clever and logical explanations is something human beings are naturally very good at. Who doesn't have a beautiful and logical explanation for why their favorite baseball team won or didn't win its division?

What makes a theory influential with scientists is when it explains lots of facts and observations, of which they are aware. That is, when a scientist reads the theory, and all kinds of facts he knows suddenly fall into place. Aha! THAT'S why this happens, and this other thing, and this other thing besides. It's when a theory suddenly explains lots of facts that it becomes persuasive to the good scientist. And that is why there are plenty of examples of theories that were "before their time" -- meaning someone thought them up, but they went nowhere, because there was no or little experimental evidence for them. This isn't tragedy, or some failure of empirical science: this is exactly how science is supposed to work. Theory must always await the experimental data that justifies it, because one of the cardinal principles of empirical science is that NOTHING must be accepted as true simply because you want it to be, or it seems reasonable to you. It must ALWAYS be based on observed fact, nothing else.