An element X belongs to $3^{\mathrm{rd}}$ period and group $13$ of the Modern Periodic Table. Write the name and the formula of the compound formed when X combines with chlorine.

The atomic number of an element '$\mathrm{X}$' is $19$. Write its electronic configuration. 

The atomic number of an element '$\mathrm{X}$' is $19$. To which period of the Modern Periodic Table does it belong and what is its valency? 

The atomic number of an element '$\mathrm{X}$' is $19$. If '$\mathrm{X}$' burns in oxygen to form its oxide, what will be its nature - acidic, basic or neutral? 

The atomic number of an element '$\mathrm{X}$' is $19$. Write the balanced chemical equation for the reaction when the oxide of this element is dissolved in water. 

The electronic configuration of four elements A, B, C, and D is given as follows: 

A- $2,8$         B-$2,8,1$

C- $2,8,2$     D- $2,8,8$

Which of them belong to the same period? Name the period. 

The electronic configuration of four elements A, B, C and D is given as follows: 

A- $2,8$        B- $2,8,1$
C- $2,8,2$     D- $2,8,8$

Which of them belong to the same group? Name the group. 

The electronic configuration of four elements A, B, C, and D is given as follows: 

A- $2,8$         B- $2,8,1$
C- $2,8,2$     D- $2,8,8$

Which amongst them would form: monovalent cation?