Waec Chemistry 1999 Past Questions and Answers

Question 1:

• WAEC 1999

Which of the following atoms contains the highest number of electrons in the outermost shell?

A. ₈O
B. ₁₀Ne
C. ₁₅P
D. ₁₉K

Question 2:

• WAEC 1999

Which of the following atoms contains the highest number of electrons in the outermost shell?

A. ₈O
B. ₁₀Ne
C. ₁₅P
D. ₁₉K

Question 3:

• WAEC 1999

What is the electronic configuration of an element represented as 19₉X?

A. 1s ²2s² 2p ⁵
B. 1s²2s²3s²3p³
C. 1s² 2s² 2p ³3s²
D. 1s ²2s²2p ⁶3s²3p₆4s ₁

Question 4:

• WAEC 1999

Pauli Exclusion Principle is related to

A. Quantum numbers of electrons
B. Reversiblility of equlibrium reactions
C. Electronegativity values of elements
D. Collision theory of reaction rates

Question 5:

• WAEC 1999

Which of the orbitals 4s, 4p, 4d and 4f has the lowest energy?

A. 4f
B. 4p
C. 4d
D. 4s