Write down the outermost electronic configurations of alkali metals. How will you justify their placement in group 1 of the periodic table?

Open in App

Solution

Answer: The outermost electronic configurations of alkali metals $n s^{1}$

All the elements fo group of group IA (or I) i.e., alkali metals have the similar outer electronic configuration i.e., $n s^{1}$ where n refers to the number of principal shell. These electronic configurations are given below.
$\begin{matrix} S y m b o l & A t o m i c n u m b e r & E l e c t r o n i c c o n f i g u r a t i o n & N o b l e g a s E l e c t r o n c o n f i g u r a t i o n L i & 3 & 1 s^{2}, 2 s^{1}, & [H e] 2 s^{1} N a & 11 & 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{1} & [N e] 3 s^{1} K & 19 & 1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2}, 3 p^{6}, 4 s^{1} & [A r] 4 s^{1} R b & 37 & 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{6}, 3 d^{10}, 4 s^{2}, 4 p^{6}, 5 s^{1} & [K r] 5 s^{1} C s & 55 & 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{6}, 3 d^{1}, 4 s^{2}, 4 p^{6}, 4 d^{10}, 5 s^{2}, 5 p^{6}, 6 s^{1} & [X e] 6 s^{1} F r & 87 & 1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2}, 3 p^{6}, 6 d^{10}, 4 s^{2}, 4 p^{6}, 4 d^{10}, 4 f^{14} 5 s^{2}, 5 p^{6} 5 d^{10}, 6 s^{2}, 6 s^{2}, 6 p^{6}, 7 s^{1} & [R n] 7 s^{1} \end{matrix}$
Hence, placement of all these elements in group 1 of the periodic table because of similarity in electronic fconfiguration and all the elements have similar properties.

Suggest Corrections

Similar questions

Justify the placement of O, S, Se, Te and Po in the same group of the Periodic Table in terms of electronic configuration, oxidation state and hydride formation.

(a) How does the chemical reactivity of alkali metals vary on going down in group 1 of the periodic table?

(b) How does the chemical reactivity of the halogens vary on going down in group 17 of the periodic table?

Q. Assertion :Alkali metals are good reducing agents. Reason: Alkali metals are the chemical elements found in Group 1 of the periodic table and have

n s^{1}

configuration, so they have high tendency to loose electron and have complete octet configuration.

Q. Write the number of periods and groups in the Modern Periodic Table. How does the metallic character of the elements vary on moving (i) from left to right in a period, and (ii) down a group ? Give reason to justify your answer.

Q. Which of the following electronic configurations in the outermost shell is characteristic of alkali metals?

Join BYJU'S Learning Program