La profecía de Mendeléiev

In 1869, Mendeleev revolutionized the periodic table by leaving gaps for undiscovered elements, predicting their properties. He accurately forecasted the existence of Gallium, which was later discovered by Paul Lekot. Gallium's properties matched Mendeleev's predictions, validating his periodic table. Gallium is a low-melting, non-toxic metal used in thermometers and electronics. Its discovery led to the acceptance of Mendeleev's system, with Scandium and Germanium filling more gaps.

What was unique about Mendeleev's periodic table compared to others at the time?

• It included all known elements.

• It was arranged alphabetically.

• It left gaps for undiscovered elements.

• It was based on atomic number.

Which element was discovered that matched Mendeleev's predictions and helped validate his periodic table?

• Germanium

• Gallium

• Silicon

• Scandium

What is a notable property of Gallium that makes it unique among metals?

• It is highly reactive with water.

• It remains liquid over a wide temperature range.

• It is the heaviest metal.

• It is magnetic.

How did the discovery of Gallium impact the scientific community's view of the periodic table?

• It led to the rejection of the periodic table.

• It had no impact on the periodic table's acceptance.

• It confirmed the validity of Mendeleev's periodic table.

• It caused confusion about the periodic table's structure.

Which elements were discovered after Gallium and filled more gaps in Mendeleev's periodic table?

• Scandium and Germanium

• Carbon and Oxygen

• Helium and Neon

• Iron and Copper