(i) The electron-dot structures for sodium, oxygen, and magnesium are: Na•, •O•, and Mg•, respectively, where the dots represent the valence electrons. (ii)The formation of Na₂O and MgO involves the transfer of electrons from metal atoms (Na and Mg) to oxygen atoms, resulting in the formation of oppositely charged ions (Na+, Mg²+, and O²⁻) that are held together by electrostatic attraction, creating ionic compounds.
Formation of Na₂O:
Two sodium atoms (Na) each lose one electron to become sodium ions (Na⁺).
An oxygen atom (O) gains these two electrons to become an oxide ion (O²⁻).
The resulting oppositely charged ions are attracted to each other, forming Na₂O.
Formation of MgO:
A magnesium atom (Mg) loses two electrons to become a magnesium ion (Mg²⁺).
An oxygen atom (O) gains these two electrons to become an oxide ion (O²⁻).
The oppositely charged ions are attracted to each other, forming MgO.(iii) It seems like the user is asking about the ions present in the compounds Na₂O, MgO, NaCl, and Na₂CO₃. Here’s a breakdown:
Na₂O (sodium oxide):: 2 sodium ions (Na⁺) and 1 oxide ion (O²⁻).
MgO (magnesium oxide):: 1 magnesium ion (Mg²⁺) and 1 oxide ion (O²⁻).
NaCl (sodium chloride):: 1 sodium ion (Na⁺) and 1 chloride ion (Cl⁻).
Na₂CO₃ (sodium carbonate):: 2 sodium ions (Na⁺) and 1 carbonate ion (CO₃²⁻).
Here’s a more detailed explanation:
Sodium (Na):
Sodium has one valence electron, so it’s represented by Na with one dot (Na•).
Oxygen (O):
Oxygen has six valence electrons, so it’s represented by O with six dots (•O•).
Magnesium (Mg):
Magnesium has two valence electrons, so it’s represented by Mg with two dots (Mg•).