- The element with atomic number 8 is Oxygen (O). Its electronic configuration is 2, 6. - To achieve a stable octet configuration in its outermost shell, Oxygen needs to gain 8 - 6 = 2 electrons, forming the O²⁻ ion. - Sodium (Na, atomic number 11) has electronic configuration 2, 8, 1 and tends to lose 1 electron to form the Na⁺ ion. - In the formation of sodium oxide (Na₂O), two sodium atoms each lose one electron, and one oxygen atom gains two electrons.
Neutral Sulfur has 16 electrons. S⁺ means it lost 1 electron (16 - 1 = 15 electrons). C) 4018Ar+: Atomic number 18. Neutral Argon has 18 electrons. Ar⁺ means it lost 1 electron (18 - 1 = 17 electrons). D) 3516S2-: Atomic number 16. Neutral Sulfur has 16 electrons. S²⁻ means it gained 2 electrons (16 + 2 = 18 electrons). Therefore, 4018Ar+ has 17 electrons, the same number as neutral 3517Cl. These species are isoelectronic. 51. The atomic number of an element is 8. How many electrons will it gain to form a compound with sodium?
Asked in UPSC NDA 2 2018 · Topic: Atomic Structure (Electronic Configurations of Multi-electron Atoms and Ions)
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