CBSE Class 10 Science
Question 7 of 45
Solved 2024 Sample Question Paper CBSE Class 10 Science — Question 7
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Question Question 7
An element 'M' has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of 'M' is:
- 10
- 12
- 14
- 18
14
Reason — Electrons are in third shell, so, first and second shells must be completely filled i.e., they have 2 and 8 electrons. Now, as third shell has half of second shell, so, there will be 4 electrons in the third shell.
Hence, 'M' will have 2+8+4 = 14 electrons.