Sourabh Monga Solutions for Chapter: Periodic Classification of Elements, Exercise 4: SELF-EVALUATION TEST

What were the two criteria used by Mendeleev in creating his periodic table? 

Why did Mendeleev leave some gaps in his periodic table? 

State the Modern Periodic Law. Discuss how Modern Periodic Table has removed the various anomalies of Mendeleev's Periodic table? 

An element $\mathrm{X}$ belongs to period $3$ and Group $2$ of the periodic table. State the number of electrons in the outermost shell of element.

An element $\mathrm{X}$ belongs to period $3$ and Group $2$ of the periodic table. What is the valency of element? 

An element $\mathrm{X}$ belongs to period $3$ and Group $2$ of the periodic table. Is it a metal or a non-metal? 

An element $\mathrm{X}$ belongs to period $3$ and Group $2$ of the periodic table. What is the formula of its hydride? 

An element $\mathrm{X}$ belongs to period $3$ and Group $2$ of the periodic table. What is the formula of its oxide?