Waec Chemistry 2008 Past Questions and Answers

Question 6:

• WAEC 2008

Atom \(^{234} _{88} Q\) decay by alpha emission to give an atom R. The atomic number and mass number of atom R are respectively

A. 86 and 230
B. 87 and 234
C. 88 and 233
D. 90 and 238

Question 7:

• WAEC 2008

Which of the following statements is not true of halogens?

A. They exist in different physical states
B. They exist as diatomic molecules
C. Their ionic radii decrease down the group
D. Their melting and bolling points increase down the group

Question 8:

• WAEC 2008

Elements in the same group of the periodic table have

A. The same number of valence electrons
B. The same number of electron shells
C. Different chemical behaviour
D. The same atomic size

Question 9:

• WAEC 2008

Consider the following elements and their electronic configurations
W: 1s²2s²
X: 1s ²2s²2p⁶
Y: 1s²2s²2p⁶3s²
Z: 1s²2s²2p⁶3s²3p². Which of the elements belong to the same group in the periodic table?

A. W and X only
B. Y and Z only
C. W and Y only
D. W, Y and Z only

Question 10:

• WAEC 2008

Arrange the following elements in order of increasing electron affinity: Br₂CI₂
I ₂
F ₂

A. I ₂CI₂Br₂F ₂
B. I ₂Br₂CI₂F ₂
C. CI₂ I ₂Br₂F ₂
D. Br₂CI₂ I ₂ F ₂