SSC GD 2023 PYQ — Question 30

The correct answer is option 3 i.e. 63.

When Mendeleev began his work, there were 63 elements known.

• The Mendeleev Periodic Table was created by Russian chemist Dmitri Mendeleev in 1869.
• He organised elements based on their atomic masses and chemical properties.
• In 1913, Henry Moseley invented the modern periodic table.