Q. 6.63 - An Introduction to General, Organic, and Biological Chemistry

Question

Using the periodic table, arrange the atoms in each of the following sets in order of increasing electronegativity: 

(a) Li, Na, K 

(b) Na, CI, P 

(c) Se, Ca, O 

Step-by-Step Solution

Answer

(a) The correct order is K, Na, Li.

(b) The correct order is Na, P, Cl.

(c) The correct order is Ca, Se, O.

Part (a) Step 1: Given Information

We have to find out the effect of electronegativity on Li, Na, K.

Part (a) Step 2: Explanation

Moving left to right across the period, the electronegativity increases and 

going down the group, the electronegativity decreases.

According to the given question,

Li, Na, and K are in $1st$ group and$2^{nd}, 3^{rd} and 4^{th}$ period, which shows that the correct order of electronegativity will be K, Na, and Li.

Hence, this is the correct order.

Part (b) Step 1: Given Information

We have to find out the effect of electronegativity from Na, Cl, P.

Part (b) Step 2: Explanation

Moving left to right across the period, the electronegativity increases and 

going down the group, the electronegativity decreases.

According to the given question,

Na, Cl, and P are in $3^{rd}$ period and $1^{st},{17}^{th} and {15}^{th}$group respectively, which shows that the correct order of electronegativity will be Na, P, and Cl.

Hence, this is the correct order.

Part (c) Step 1: Given Information

We have to find out the effect of electronegativity on Se, Ca and O.

Part (c) Step 2: Explanation

Moving left to right across the period, the electronegativity increases and

going down the group, the electronegativity decreases 

According to the given question,

Se and Ca are in $4^{th}$ period and ${16}^{th} and 2^{nd}$group respectively, while O is in $2^{nd}$ period and group, which shows that the correct order of electronegativity will be Ca, Se, and O.

Hence, this is the correct order.