WAEC Chemistry 2019 Objective — Question 7
Question 7 of 50 from the West African Examinations Council (WAEC) Chemistry 2019 Objective paper, with the correct answer and a full explanation.
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Calcium and magnesium belong to the same group of the periodic table because both
- A. are metals
- B. form cations
- C. form colourless salts
- D. have same number of valence electronsCorrect
Explanation
Elements in the same group have the same number of valence (outermost) electrons. Ca (2,8,8,2) and Mg (2,8,2) both have 2 valence electrons, placing them in Group II.
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