uestion 7 (2 points)

Question

Select the statements below that are true about Mendeleev and the development of the Periodic Table.

Question 7 options:

Mendeleev was the only person to develop a periodic table.

Mendeleev invented all the elements on the Periodic Table.

The Periodic Table was developed by NASA.

Mendeleev's table was complete.

Using his table, Mendeleev was able to predict elements that hadn't been discovered yet.

Mendeleev organized elements by atomic weight.

Answer 1

The true statements about Mendeleev and the development of the Periodic Table are:

1. Using his table, Mendeleev was able to predict elements that hadn't been discovered yet. - True, Mendeleev predicted several elements and their properties before they were discovered.

2. Mendeleev organized elements by atomic weight. - True, he arranged the elements primarily by atomic weight and noticed periodic trends in their properties.

The other statements are false:

• Mendeleev was the only person to develop a periodic table. - False, there were other scientists like Lothar Meyer who also developed similar periodic tables independently.
• Mendeleev invented all the elements on the Periodic Table. - False, he did not invent elements; he organized known elements.
• The Periodic Table was developed by NASA. - False, the Periodic Table was developed long before NASA was established.
• Mendeleev's table was complete. - False, while Mendeleev's table was groundbreaking, it was not complete; there were still unknown elements and the arrangement was later refined with the discovery of atomic numbers.