An element X having atomic number “Z=27” belongs to which block of periodic table?
Correct answer: C. d-block
- A. s-block
- B. p-block
- C. d-block
- D. f-block
Explanation
Z equal to 27 is cobalt, with configuration [Ar] 3d7 4s2, and since its last electron enters a d orbital it is a d block element. s block elements end in s1 or s2 with no d electrons in the valence shell, and p block elements fill p orbitals.
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About Blocks of the Periodic Table
Electron configurations divide elements into s, p, d and f blocks according to the subshell receiving the last electron. Work includes the positions, valence-shell configurations and general properties of s-block and p-block elements, along with periodic trends in atomic size, ionisation energy, electron affinity and electronegativity.
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