Question

The electronic configuration of metal 'M' is 1s22s1 and of the non metal 'X' is 1s22s22p3. When these two elements combines, the formula of
the compound will be
O MX3
ОМ,Х
O M2X3
O M3X2​

Answer 1

Answer:-

Given:

Electronic configuration of a metal "M" is 1s² 2s¹ and a non metal "X" is 1s² 2s² 2p³.

Valency of "M" = 1

(number of Valence electrons in the last shell)

Valency of "X" = 8 - 5 = 3

(If the number of Valence electrons are greater than 4 then the valency of the element = 8 - number of Valence electrons)

Using criss - cross method,

That is,

Writing their valencies on the top.

$\sf \implies \large{{M}^{ + 1} \: {X}^{ - 3} }$

$\sf \implies \large{M_{3}X}$

Hence, the formula of the compound would be M3X.

Criss - Cross Method:

This method is used to write the formula of a compound formed by a certain number of elements through their valencies.

How to write formula of a compound:

1) Write the symbol of positive ion (metal) or the radical to the left and for the negative ion (non metal) or the radical to the right.

2. Put the Valency number of each ion on its top. Divide the Valency numbers by highest common factor, if any to get simple ratio.

3) Now , ignore the "+" and "-" symbols and interchange the Valency numbers of the ions.

4) Shift the valency numbers to lower right side of the ion. If the radical receives a number more than 1, enclose it with brackets. (Do not enclose ions with brackets)

Hence, we get the formula of the compound formed.

Answer 2

Explanation:

Given:

Electronic configuration of a metal "M" is 1s² 2s¹ and a non metal "X" is 1s² 2s² 2p³.

Valency of "M" = 1

(number of Valence electrons in the last shell)

Valency of "X" = 8 - 5 = 3

(If the number of Valence electrons are greater than 4 then the valency of the element = 8 - number of Valence electrons)

Using criss - cross method,

That is,

Writing their valencies on the top.

$\sf \implies \large{{M}^{ + 1} \: {X}^{ - 3} }⟹M </p><p>$

$\sf \implies \large{M_{3}X}⟹M$

Hence, the formula of the compound would be M3X.

Criss - Cross Method:

This method is used to write the formula of a compound formed by a certain number of elements through their valencies.

How to write formula of a compound:

1) Write the symbol of positive ion (metal) or the radical to the left and for the negative ion (non metal) or the radical to the right.

2. Put the Valency number of each ion on its top. Divide the Valency numbers by highest common factor, if any to get simple ratio.

3) Now , ignore the "+" and "-" symbols and interchange the Valency numbers of the ions.

4) Shift the valency numbers to lower right side of the ion. If the radical receives a number more than 1, enclose it with brackets. (Do not enclose ions with brackets)

Hence, we get the formula of the compound formed.