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Chemistry Past Questions and Answers

Topic: Atomic number

Jamb Chemistry Questions - Atomic number

Question 1:
Which of the following is the electronic configuration of sodium?
(Atomic number of Na = 11)
  • A 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>2</sup>
  • B 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>2</sup> 3p1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>1</sup>
  • C 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>1</sup>
  • D 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>°</sup>
  • E 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 4s<sup style='font-size: smaller;'>1</sup>
View Answer & Explanation
Question 2:
What is the atomic number of aluminium?
  • A 13
  • B 26
  • C 14
  • D 12
View Answer & Explanation