1. A dot represents a valence electron.
QUESTION:
How many electrons are shared between the carbon and nitrogen atoms shown in the Lewis structure below? A. 3, B. 4, C. 6, D. 8
Triple bond
Single bond
Lone pair
In a Lewis structure:
A dot represents a valence electron.
Dots shown between symbols for two atoms are valence electrons shared by the two atoms.
A line represents a pair of dots.
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How many electrons are shared between the carbon and nitrogen atoms of the Lewis structure shown here…. 3… 4… 6…, or 8.
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In a Lewis structure, a dot represents a valence electron.
Dots shown between symbols for two atoms are valence electrons shared by the two atoms
CLICK A line is usually drawn instead of a pair of dots.
If we look at the structure, we can see that there are three lines drawn between Carbon and Nitrogen.
HIGHLIGHT TRIPLE BOND BETWEEN C AND N
Each line represents a pair of dots, or a pair of shared valence electrons.
Therefore, as shown here, carbon and nitrogen are sharing three pairs of electrons. 3 times 2 is six. The correct answer is six.
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Here’s another way that this structure might be drawn.
And here’s another way.
Since there are three pairs of electrons shared between carbon and nitrogen, we say that
the carbon-to-nitrogen is a triple covalent bond, or a triple bond.
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The structure shown here illustrates the octet or duet rule. When nonmetals share electrons, they do so in a manner that makes it seem like the atoms are surrounded by eight valence electrons, or by two electrons in the case of hydrogen. In doing so, we say that the atoms becomes noble-gas-like. In the example shown here, nitrogen appears to be surrounded by eight valence electrons…
Six shared in the triple bond with carbon,
and two unshared…
The unshared pair is called a lone pair
Similarly, carbon as shown here is surrounded by eight valence electrons…
Six in the triple bond with nitrogen…
And Two in the single bond with hydrogen…
Nitrogen and Carbon follow the octet rule.
Hydrogen, on the other hand, appears to be surrounded by two electrons
Recall that a hydrogen atom has only one electron, and needs just one more electron to be isoelectronic with the noble gas helium.
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We say that hydrogen follows the duet rule. The only way hydrogen bonds with other atoms is through a single bond.
This makes it seem like it is surrounded by two valence electrons.
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The structure shown here illustrates octet/duet rule. Atoms tend to become “noble-gas-like”

3. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08