Question

Mendeleev predicted the existence of some undiscovered elements based on his periodic table.

• A. True
• B. False

Answer 1

The correct option is A True

When Mendeleev proposed his periodic table, he noted gaps in the table and predicted that unknown elements exist with properties appropriate to fill those gaps.

The four predicted elements- eka-boron ($E_b$ ), eka-aluminium ($E_a$ ), eka-manganese ( $E_m$) and eka-silicon ($E_s$ ) proved to be good predictors of the properties of scandium, gallium, technetium and germanium respectively, with each filling the spot in the periodic table assigned by Mendeleev.