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Assertion (A): The atomic and ionic radi...

Assertion (A): The atomic and ionic radii generally decrease towards right in a period.
Reason (R): The ionisation enthalpy increases on moving towards left in a period.

A

Both A and R are true and R is the correct explanation of A.

B

Both A and R are true but R is NOT the correct explanation of A.

C

A is true but R is false.

D

A is false and R is true.

Text Solution

AI Generated Solution

The correct Answer is:
To analyze the given assertion and reason, we will break down the concepts involved step by step. ### Step 1: Understanding the Assertion **Assertion (A)** states that "The atomic and ionic radii generally decrease towards the right in a period." - **Explanation**: As we move from left to right across a period in the periodic table, the number of protons in the nucleus increases. This increase in positive charge pulls the electrons closer to the nucleus, resulting in a decrease in atomic and ionic radii. ### Step 2: Understanding the Reason **Reason (R)** states that "The ionization enthalpy increases on moving towards the left in a period." - **Explanation**: Ionization enthalpy is the energy required to remove an electron from an atom. As we move from left to right in a period, the ionization enthalpy generally increases because the electrons are held more tightly by the nucleus due to the increased positive charge. Therefore, the statement in the reason is incorrect because it suggests that ionization enthalpy decreases towards the left, which is not true. ### Step 3: Evaluating the Assertion and Reason - The assertion is **true** because atomic and ionic radii do decrease from left to right across a period. - The reason is **false** because ionization enthalpy actually increases from left to right, not decreases. ### Conclusion The assertion is true, but the reason is false. Therefore, the correct interpretation of the relationship between the assertion and reason is that the assertion stands alone as a true statement, while the reason does not support it. ### Final Answer - Assertion (A) is true. - Reason (R) is false. ---
To analyze the given assertion and reason, we will break down the concepts involved step by step. ### Step 1: Understanding the Assertion **Assertion (A)** states that "The atomic and ionic radii generally decrease towards the right in a period." - **Explanation**: As we move from left to right across a period in the periodic table, the number of protons in the nucleus increases. This increase in positive charge pulls the electrons closer to the nucleus, resulting in a decrease in atomic and ionic radii. ### Step 2: Understanding the Reason ...
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The periodicity is related to the electronic configuration. That is, all chemical and phyical properties are a manifestation of the electronic configurfation of the elements. The atomic and ionic radii generally decrease in a preiod from left or right. As a consequence , the ionisation enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionisation enthalpy of the extreme left element in a period is the least and the electron left element on the extreme right is the highest negative. This results into high chemical reactivity at two extgremes and the lowest in the centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease (with excetption in some third period elements) in electron gain enthalpies in the case of main group elements . These properties can be related with the (i) reducing and oxidising behacviour of the elements (ii) metallic and no-metallic charcter of element (iii) acidic, basic , amphoteric and neutral character of the oxides of the elements. Which of the following statement is incorrect?

The periodicity is related to the electronic configuration. That is, all chemical and phyical properties are a manifestation of the electronic configurfation of the elements. The atomic and ionic radii generally decrease in a preiod from left or right. As a consequence , the ionisation enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionisation enthalpy of the extreme left element in a period is the least and the electron left element on the extreme right is the highest negative. This results into high chemical reactivity at two extgremes and the lowest in the centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease (with excetption in some third period elements) in electron gain enthalpies in the case of main group elements . These properties can be related with the (i) reducing and oxidising behacviour of the elements (ii) metallic and no-metallic charcter of element (iii) acidic, basic , amphoteric and neutral character of the oxides of the elements. Which of the following statement is incorrect?

The periodicity is related to the electronic configuration. That is, all chemical and phyical properties are a manifestation of the electronic configurfation of the elements. The atomic and ionic radii generally decrease in a preiod from left or right. As a consequence , the ionisation enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionisation enthalpy of the extreme left element in a period is the least and the electron left element on the extreme right is the highest negative. This results into high chemical reactivity at two extgremes and the lowest in the centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease (with excetption in some third period elements) in electron gain enthalpies in the case of main group elements . These properties can be related with the (i) reducing and oxidising behacviour of the elements (ii) metallic and no-metallic charcter of element (iii) acidic, basic , amphoteric and neutral character of the oxides of the elements. Among Al_(2)O_(3), SiO_(2),P_(2)O_(3) and SO_(2) the correct order of acid strenght is :

The periodicity is related to the electronic configuration. That is, all chemical and phyical properties are a manifestation of the electronic configurfation of the elements. The atomic and ionic radii generally decrease in a preiod from left or right. As a consequence , the ionisation enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionisation enthalpy of the extreme left element in a period is the least and the electron left element on the extreme right is the highest negative. This results into high chemical reactivity at two extgremes and the lowest in the centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease (with excetption in some third period elements) in electron gain enthalpies in the case of main group elements . These properties can be related with the (i) reducing and oxidising behacviour of the elements (ii) metallic and no-metallic charcter of element (iii) acidic, basic , amphoteric and neutral character of the oxides of the elements. Among Al_(2)O_(3), SiO_(2),P_(2)O_(3) and SO_(2) the correct order of acid strenght is :

The periodicity is related to the electronic configuration. That is, all chemical and physical properties are a manifestation of the electronic configuration of the elements. The atomic and ionic radii generally decrease in a period from left to right. As a consequence, the ionization enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionization enthalpy of the exterme left element in a period is the least and teh electron gain enthalpy of the element on the exterme right is the highest negative. This results into high chemical reactivity at the two extermes and the lowest in he centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease in ionization enthalpies and a regular decrease (with exception in some third period elements) in electron gain enthalpies in the case of main group elements. The loss and gain of electrons can be co-related with the reducting and oxidising behaviour, and also with metallic and non-metallic character respectively, of the elements. The correct order of the metallic character is:

The periodicity is related to the electronic configuration. That is, all chemical and physical properties are a manifestation of the electronic configuration of the elements. The atomic and ionic radii generally decrease in a period from left to right. As a consequence, the ionization enthalpies generally increase and electron gain enthalpies become more negative across a period. In other words, the ionization enthalpy of the exterme left element in a period is the least and teh electron gain enthalpy of the element on the exterme right is the highest negative. This results into high chemical reactivity at the two extermes and the lowest in he centre. Similarly down the group, the increase in atomic and ionic radii result in gradual decrease in ionization enthalpies and a regular decrease (with exception in some third period elements) in electron gain enthalpies in the case of main group elements. The loss and gain of electrons can be co-related with the reducting and oxidising behaviour, and also with metallic and non-metallic character respectively, of the elements. Which of the following statements is correct?

The periodicity is related to the electronic configuration. That is, all chemical and physical properties are a manifestation of the electronic configuratio of the elements. The atomic and ionic radii generally decrease in a period from left to right. As a consequence, the ionization enthalpes generally increase and electron gain enthalpies become more negative across a period. In order words, the ionization enthalpy of the extreme left element in a period is the least and the electron gain enthalpy of the element on the extreme right is the highest negative. This results into high chemical reactivity at the two extremes and the lowest in the centre. Similary, down the group, the increase in ionization enthalpies and a regular decrease (with exception in some third period elements) in electron gain enthalpies in the case of main group elements. The loss and gain of electrons can be co-related with the reducing and oxidising behaviour, and also with metallic and non-metallic character respectively of the elements. The correct order of the metallic character is:

The periodicity is related to the electronic configuration. That is, all chemical and physical properties are a manifestation of the electronic configuratio of the elements. The atomic and ionic radii generally decrease in a period from left to right. As a consequence, the ionization enthalpes generally increase and electron gain enthalpies become more negative across a period. In order words, the ionization enthalpy of the extreme left element in a period is the least and the electron gain enthalpy of the element on the extreme right is the highest negative. This results into high chemical reactivity at the two extremes and the lowest in the centre. Similary, down the group, the increase in ionization enthalpies and a regular decrease (with exception in some third period elements) in electron gain enthalpies in the case of main group elements. The loss and gain of electrons can be co-related with the reducing and oxidising behaviour, and also with metallic and non-metallic character respectively of the elements. The correct order of the non-metallic character is: