The diagram shows the outer electrons of a magnesium atom and an oxygen atom as they react. Use the two crosses on the magnesium to state how many electrons...
Question 1 Report
The diagram shows the outer electrons of a magnesium atom and an oxygen atom as they react. Use the two crosses on the magnesium to state how many electrons the magnesium atom loses.
Answer Details
Count the crosses on the magnesium atom in the diagram: there are two, and each cross represents one outer-shell electron. Magnesium is in Group II with the arrangement 2,8,2, so those two electrons are its entire outer shell. Losing both leaves the stable full arrangement 2,8, so the magnesium atom loses 2 electrons and becomes Mg2+.
The arrow in the diagram shows those two electrons moving across to the oxygen atom, which has six outer electrons drawn and needs exactly two more to reach eight. That perfect match is why magnesium oxide has the formula MgO.
Answering 3 would suit aluminium, not magnesium. The number of outer-shell dots or crosses drawn is the direct clue, so count them before deciding.
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