TOEFL Listening III

In the beginning of the lecture a student asks a question about the periodic table. How does the story of element 43 answer her question?

• By providing an example of an element whose place in the periodic table was moved

• By providing an example of an element whose existence was predictable from the periodic table

• By providing an example of an element which scientists predicted was formed from uranium

• By providing an example of an element that can only be made artificially

What does the professor say about early versions of the periodic table?

• Early versions listed two names for some elements.

• Early versions had the incorrect atomic number for some elements.

• Early versions were not as easy to use as modern versions.

• Early versions did not list an element for every atomic number.

What fact inspired researchers to give the name “technetium” to element 43?

• The element was radioactive.

• The element was derived from uranium.

• The element was created artificially.

• The element was found using x-ray spectroscopy.

What characteristic of element 43 might explain why the scientific community doubted the findings of Ida Tacke’s team?

• Element 43 has a very fast rate of decay

• Element 43 always contains small amounts of other elements.

• Element 43 cannot be created artificially.

• Element 43’s radioactivity makes it easy to isolate and measure.

What does the professor believe about the claim that Ida Tacke’s team made about element 43?

• Scientists should have accepted the claim when it was first published.

• There is not enough evidence to know if the team actually discovered element 43.

• The team’s unusual scientific methods were unreliable.

• If the team’s ore sample had contained element 43, the team would have been able to isolate a weighable amount.

Professor And you know, here’s an incredible irony. Ida Tacke, the chemist who led the masurium team … well, she was the first to suggest that uranium could break up into smaller pieces. But she didn’t know that that was the defense of her own discovery of element 43!

What does the professor imply about the chemist Ida Tacke when he says this: Professor But she didn’t know that that was the defense of her own discovery of element 43!

• She did not realize that the periodic table predicted the radioactivity of element 43.

• She did not understand why her team’s findings were dismissed by the scientific community

• Her theory about uranium would have explained the presence of element 43 in her team’s ore sample.

• Her theory about uranium would have explained the errors that created element 43 in a cyclotron.