Table of Contents
- 1 Why do expanded octets occur?
- 2 What is the reason for the octet rule?
- 3 What periods can have expanded octets?
- 4 What elements have incomplete octets?
- 5 What is the element with 16 electrons?
- 6 Why does aluminum not form complete octets of valence electrons when forming covalent compounds?
- 7 When can atoms have expanded octets?
- 8 What is an incomplete octet compound give an example?
- 9 Why is boron considered an incomplete octet?
- 10 What are the three exceptions to the octet rule?
Why do expanded octets occur?
Expanded octet occurs when an atom is able to have more than 8 valence electrons. For example, in SO₃, the sulfur atom forms 6 covalent bonds, hence it has 12 valence electrons.
What is the reason for the octet rule?
Why Elements Follow the Octet Rule Atoms follow the octet rule because they always seek the most stable electron configuration. Following the octet rule results in completely filled s- and p- orbitals in an atom’s outermost energy level.
Which elements can have incomplete octets?
The two elements that most commonly fail to complete an octet are boron and aluminum; they both readily form compounds in which they have six valence electrons, rather than the usual eight predicted by the octet rule.
What periods can have expanded octets?
The Expanded Octet Main group elements in the third period and below form compounds that deviate from the octet rule by having more than 8 valence electrons.
What elements have incomplete octets?
What elements have expanded octets?
Sulfur, phosphorus, silicon, and chlorine are common examples of elements that form an expanded octet. Phosphorus pentachloride (PCl5) and sulfur hexafluoride (SF6) are examples of molecules that deviate from the octet rule by having more than 8 electrons around the central atom.
What is the element with 16 electrons?
Sulfur
How to Write the Electron Configuration for Sulfur (S) In order to write the Sulfur electron configuration we first need to know the number of electrons for the S atom (there are 16 electrons). When we write the configuration we’ll put all 16 electrons in orbitals around the nucleus of the Sulfur atom.
Why does aluminum not form complete octets of valence electrons when forming covalent compounds?
Ernest Z. In some of its compounds, aluminum violates the octet rule by having only six valence electrons. For example, aluminum chloride, AlCl₃, has only six valence electrons around the Al atom.
What atoms have expanded octets?
When can atoms have expanded octets?
To have an expanded octet (more than 8 electrons) you need more than 4 orbitals.
What is an incomplete octet compound give an example?
Less common than hypervalent compounds, but by no means rare, are species in which an atom does not achieve an octet of electrons. Such compounds are called incomplete-octet compounds. An example is the compound boron trifluoride, BF 3, which is used as an industrial…
Why is bf_4^- an incomplete octet?
Each situation with an incomplete octet is a little different. It revolves around the central idea that the form with the incomplete octet is lower in energy than the form with a complete octet. BF_4^- will be high energy. There simply isn’t enough attraction from the nucleus to keep the fourth fluorine in place.
Why is boron considered an incomplete octet?
Essentially, those hydrogen partly belong to both boron atoms creating a hint of a full octet. Boron is a good candidate for incomplete octets as it only has three electrons in its highest energy level while still having a small nucleus. This doesn’t mean its the only example of incomplete octets however.
What are the three exceptions to the octet rule?
There is always an exception, and in this case, three exceptions: When there are an odd number of valence electrons When there are too few valence electrons When there are too many valence electrons The first exception to the Octet Rule is when there are an odd number of valence electrons.