Loading the lesson
Loading the lesson
Search AllRounder.ai
Search the courses, subjects, tracks, games and features, or jump straight to a page.
Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Good morning, class! Today, we will delve into covalent bonds. A covalent bond forms when two atoms share electrons. Can anyone tell me why atoms might want to share electrons?
To fill their outer electron shell and become stable!
Exactly! This is why we often talk about the 'octet rule.' To help you remember, think of the octet rule as the '8 is great' principle. Now, how can we represent these shared electrons visually?
Using Lewis dot structures!
Spot on! Lewis dot structures allow us to visualize how the electrons are shared. Let's sketch the structure for H2 together. Who wants to draw it?
I can do it! We just put one H atom with one dot and the other H with another dot, and connect them.
Great job! That shows the single covalent bond. Remember: single bonds are denoted by sharing a pair of electrons!
To summarize, covalent bonds form by electron sharing, achieving stability through the octet rule. Let's move to types of covalent bonds!
Now that we covered single covalent bonds, what happens when two atoms share more than one pair of electrons?
They form double or triple bonds!
That's right! For instance, in carbon dioxide (CO2), we have double bonds. Can anyone sketch that structure?
There would be one carbon in the middle and two oxygens at the ends, with two pairs of electrons between each pair.
Perfect! And what about nitrogen? What bond does nitrogen form in N2?
That would be a triple bond, right?
Exactly! So to summarize, one atom sharing one pair of electrons forms a single bond, while sharing two or three pairs forms double or triple bonds. Let’s practice with some Lewis structures!
Now, how does knowing about covalent bonds help us predict molecular geometry?
It helps us understand the shape based on how the bonding and lone pairs around the central atom repel each other.
Correct! This is known as the VSEPR theory. Does anyone remember the order of repulsion strengths?
It's lone pair-lone pair > lone pair-bond pair > bond pair-bond pair!
Awesome! So it affects the angles in those shapes too. Let's now attempt to predict the shape of water using the VSEPR model.
Since water has two bonding pairs and two lone pairs, it should have a bent shape.
Exactly! And as a recap, covalent bonds not only determine how atoms connect but also how those connections shape the entire molecule.
In a bond that’s covalent, electrons share, rounding each soul with love and care.
Imagine two best friends sharing their toys to make a bigger one; that’s like atoms sharing electrons to form a bond.
Remember: O for Octet with Eight, bonds are great - Single, Double, Triple, electrons create!
BOND: "B"onded, "O"xygen, "N"itrogen, "D"ouble for sharing!
Term
What is a covalent bond?
Click to flip
Term
What is a Lewis dot structure?
Click to flip
A chemical bond formed by the sharing of electrons between two atoms.
A diagram that shows the valence electrons in an atom as dots and illustrates how they are shared in bonds.
The observation that atoms tend to bond in such a way that they each have eight electrons in their valence shell.
A covalent bond involving one pair of shared electrons.
A covalent bond involving two pairs of shared electrons.
Covalent bonds form through the sharing of electron pairs between atoms, leading to stable molecules and distinct molecular shapes.
This section explores the concept of covalent bonding as articulated by Lewis and Langmuir, explaining how atoms achieve stable electron configurations through electron sharing. It delves into the formation of single, double, and triple bonds, and introduces Lewis dot structures as a way to visualize these bonds.
Covalent bonds are created when atoms share electrons, allowing them to achieve a full valence shell and connect in stable configurations. Langmuir refined Lewis's original postulation, explaining covalent bonds as the result of electron sharing. The sharing involves two atoms contributing at least one electron to form a pair that constitutes a bond. This section introduces Lewis dot structures, allowing for the representation of molecules.
Key Types of Covalent Bonds:
In addition to introducing these concepts, the section emphasizes the need for understanding molecular geometry, which can be predicted based on the number of bonding and lone pairs of electrons around the central atom. The knowledge of such bonding types lays the groundwork for further explorations into molecular structure, stability, and reactivity.