An element M has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of M is:
The correct option is (c) 14. Silicon has the electronic configuration 2,8,4. Here, the second shell contains 8 electrons, while the third shell contains 4 electrons, which is exactly half of the second shell, satisfying the given condition.
Science important questions Final Exam 2025 Class 10
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The correct option is (c) 14. The element with atomic number 14 is silicon, whose electronic configuration is 2,8,4. The second shell contains 8 electrons, and the third shell has 4 electrons, which is exactly 50% of 8. This satisfies the condition given in the question. Hence, silicon with atomic number 14 forms the correct answer, while other options do not match the condition.