In which compounds do the central atoms not obey the octet rule? A) NH3
BH3 does not follow the octet rule. The octet rule says that atoms tend to gain, lose or share electrons so as to have eight electrons in their outer electron shell.
In this case, boron (B) has 3 electrons, and each hydrogen (H) has one electron. Boron will be the central element, and its electrons will configure themselves so that there will be one electron on three sides of it (say one electron on the left side of boron, one electron on the right side, and one electron on the bottom). Each hydrogen atom will bond where a boron electron is, so that hydrogen and boron are “sharing” electron pairs. These electron pairs create a bond that holds the components of the BH3 compound together.
Notice that when you draw the configuration described above, boron only has 6 (not 8) electrons around it. This is why it does not obey the octet rule like the other compounds given in the problem do.
The connection between the octet rule and the inert gases is what drives the importance of the octet rule. Why do we say that having eight outermost electrons is stable? The inert gases are those which do not form chemical bonds or very few bonds. Chemical bonds form in order to get to a lower energy level where the electron arrangement is most stable. Clearly, whatever arrangement the inert gases have must be particularly stable. All inert gases (except He) have completely filled ns and np sublevels for a total of 8 outermost electrons. We’ve can also see that many ions are isoelectronic with the inert gases meaning that they are particularly stable as well. And all of this with 8 outermost electrons, hence the octet rule.
answer is B and E because in NO2 there are 9 electrons around nitrogen. and for BH3 there are only 6 electrons around boron.
Check previous questions.
I think yesterday someone asked the very same thing…
And I think the answer was E.
well i believe the answer is ‘e’
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