Modern periodic law and periodic table, s, p, d, f blocks
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See all →- Which among the following electronic configurations belong to main group elements?A. [Ne]3s^1 B. [Ar]3d^3 4s^2 C. [Kr]4d^105s^2 5p^5 D. [Ar]3d^104s^1 E. [Rn]5f^0 6d^2 7s^2Choose the correct answer from the option given below : Answer: 2. A and C only Key idea: main group elements are s- and p-block elements; d-block elements have d electrons being filled. A: [Ne]3s... 1
- Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :Assertion A : Metallic sodium dissolves in liquid ammonia giving a deep blue solution, which is paramagnetic.Reasons R : The deep blue solution is… Answer: 4. A is true but R is false. Key idea: Sodium in liquid ammonia gives ammoniated electrons. Na + (x+y)NH₃ → [Na(NH₃)_x]^+ + [e(NH₃)_... 1
- Which one of the following statements is correct? Answer: 2. The daily requirement of Mg and Ca in the human body is estimated to be 0.2 - 0.3 g. Key idea: Recall the biological roles of Mg... 1
- Match List - I with List - II.List - I: (a) Li (b) Na (c) KOH (d) CsList - II: (i) absorbent for carbon dioxide (ii) electrochemical cells (iii) coolant in fast breeder reactors (iv) photoelectric cellChoose the correct answer from the options given… Answer: 1. (a) - (ii), (b) - (iii), (c) - (i), (d) - (iv) Key idea: recall the uses of alkali metals and their compounds. Li: electrochemica... 1
- Identify the incorrect statement from the following Answer: 3. The oxidation number of K in KO₂ is +4 . Key idea: in superoxide KO₂ , oxygen is O₂^- , so K is +1. Alkali metals always show +1.... 1
- The IUPAC name of an element with atomic number 119 is Answer: 2. ununennium Key idea: IUPAC temporary names use numerical roots: 0 = nil, 1 = un, 9 = enn, ending in -ium. Z = 119 means digits 1,... 1