atom outer-shell electrons bonds formed hydrogen 1 1 oxygen 6 2 nitrogen 5 3 carbon 4 4 The diagram shows the electron shells of a single atom. An atom comp...
Question 1 Report
| atom | outer-shell electrons | bonds formed |
|---|---|---|
| hydrogen | 1 | 1 |
| oxygen | 6 | 2 |
| nitrogen | 5 | 3 |
| carbon | 4 | 4 |
The diagram shows the electron shells of a single atom. An atom completes its outer shell by forming enough covalent bonds to reach eight outer electrons. Using the table, how many covalent bonds does the atom shown form?
Answer Details
Count only the electrons on the outermost ring. The diagram shows 2 electrons on the inner shell and 6 on the outer shell, so the atom has 6 outer-shell electrons, which matches the oxygen row of the table, and that row gives 2 bonds.
The reason is the rule stated in the question: the outer shell is complete at eight electrons, so the number of covalent bonds needed is \(8 - 6 = 2\). Each covalent bond brings in one shared electron from the other atom, which is why oxygen forms two bonds, as in H-O-H.
Answering 4 uses the carbon row and answering 3 uses the nitrogen row; both come from misreading how many electrons sit on the outer ring. Count the outer shell first, then read across.
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