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Friday, 12 June 2026
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Chemistry Past Questions and Answers

Waec Chemistry Questions

Question 316:
The positive of an element in the Periodic Table is determined by
  • A Its density
  • B Its atomic radius
  • C Its relative atomic mass
  • D The number of protons in its atom
  • E The number of neutrons in its atom
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Question 317:
Which of the following electronic structures belongs to a noble gas?[sup][/sup]
  • A 1s22s2
  • B 1s 22s22p4
  • C 1s22s22p63s23p6
  • D 1s22s22p2
  • E 1s22s22p 63s23p3
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Question 318:
In a chemical reaction, the reacting species possess energy of motion known as
  • A Potential energy
  • B Free energy
  • C Bond energy
  • D Kinetic energy
  • E Hydration energy
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Question 319:
The following compounds will decompose on heating except
  • A NaHCO3
  • B K2CO3
  • C MgCO3
  • D Ca(HCO3)2
  • E ZnCO3
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Question 320:
Which of the following reactions is accompanied by the first ionization energy of an element X?
  • A X +(aq) → X 2+(aq) + e-
  • B X -(g) → X(g) + e-
  • C X+(g) → X2+ +e-
  • D X (g) → X+(g) +e-
  • E X(s) → X +(g) + e-
View Answer & Explanation