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Sodium And Aluminum Have Atomic Numbers 11 and 13, Respectively. They Are Separated by One Element in the Periodic Table and Have Valencies 1 and 3 Respectively. - Chemistry

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Question

Sodium and aluminum have atomic numbers 11 and 13, respectively. They are separated by one element in the periodic table and have valencies 1 and 3 respectively. Chlorine and potassium are also separated by one element in the periodic table (their atomic numbers being 17 and 19, respectively) and yet both have valency 1. Explain.

Short Note

Solution

Na and Al have the capacity to donate an electron due to which the valency is positive, whereas Cl and K can only gain or lose one electron due to which their valency is -1 and +1, respectively. This is the only difference between these two.

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Chapter 5: The Periodic Table - Exercise 5 (B) [Page 89]

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Selina Concise Chemistry [English] Class 9 ICSE
Chapter 5 The Periodic Table
Exercise 5 (B) | Q 10 | Page 89

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