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chemistry igcse acapprinted 133 · PDF 133
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printed 133 · PDF 133
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133
ANS: The answer is D, because Ionic compounds such as MgO always exist as ionic lattices where cations
and anions are bonded together. A is incorrect because magnesium oxide has ionic bonding, not covalent. B
is incorrect because in a solid, individual ions cannot move freely. C is incorrect because electrons cannot
move freely through an ionic lattice, as they are donated by metal atoms to non-metal atoms to form cations
and anions.
Q13. 0620_w22_qp_22
ANS: The answer is D, because Each Nitrogen atom needs three electrons to complete its octet. So, each of
the two nitrogen atoms share three pairs of bonded electrons with each other.
Q14. 0620_w22_qp_22
ANS: The answer is B, because Metals consist of positive metal ions (option 1) in a sea of delocalized
electrons (option 4). Option 2 is incorrect because only positive ions exist in a metal lattice. Option 3 is
incorrect because electrons are shared in covalent compounds, not metal lattices.
Chemical equilibrium:
1. Anhydrous cobalt(II) chloride is blue and turns pink when water is added. How is this reaction reversed?
A Adding dilute acid
B Filtering
C Heating
D Cooling