Waec Chemistry 2003 Past Questions and Answers

Question 1:

• WAEC 2003

The electronic configuration of an element is 1s ²2s₂2p₆3s ₂
3p₃. Where is the element located in the periodic table?

A. Group lll, period 3
B. Group lll, period 5
C. Group V, period 3
D. Group V, period 5

Question 2:

• WAEC 2003

The electronic configuration of an element is 1s ²2s₂2p₆3s ₂
3p₃. Where is the element located in the periodic table?

A. Group lll, period 3
B. Group lll, period 5
C. Group V, period 3
D. Group V, period 5

Question 3:

• WAEC 2003

Group O of elements are unreactive because

A. Their outmost shells contain equal number of electrons
B. Their highest occupied enegy level is full
C. They are monatomic gases
D. They are non-metals

Question 4:

• WAEC 2003

An element X with electronic configuration 1s₂2s₂2p ₆3s ₂3p₅combines with another element Y with the configuration 1s_{[/sub]2s[sub]2}2p₂3s₃3p₅. What is the formula of the compound formed?

A. X₂Y₅
B. X₂Y₃
C. XY₃
D. XY₂

Question 5:

• WAEC 2003

Which of the following statements about dative bonding is not correct?

A. There is sharing of electrons
B. One atom must possess a lone pair electrons
C. Each participating atom contributes one electron
D. It can be formed between molecules