Besides gallium, which other elements have since been discovered that were left by Mendeleev in his Periodic Table? (any two)
Element $X$ forms a chloride with the formula $XCl_2$, which is a solid with a high melting point. $X$ would most likely be in the same group of the Periodic Table as
What were the limitations of Newlands’ Law of Octaves ?
The position of three elements $A$, $B$ and $C$ in the Periodic Table are shown below
Group $16$ | Group $17$ |
- | - |
- | $A$ |
- | - |
$B$ | $C$ |
$(a)$ Will $C$ be larger or smaller in size than $B$ ?
$(b) $ Which type of ion, cation or anion, will be formed by element $A$ ?
How could the Modern Periodic Table remove various anomalies of Mendeléev’s Periodic Table ?