Chemical Bonding: Covalent Bonding Lewis Dot Diagrams

Summary

In this video, Miss Martins explains the concept of covalent bonding, focusing on how atoms share electrons to form stable molecules. She distinguishes covalent bonds from ionic bonds, emphasizing that covalent bonding occurs between non-metals. Miss Martins also demonstrates how to identify valence electrons using the periodic table and introduces Lewis Dot diagrams to visually represent bonding. The video covers examples like hydrogen, chlorine, and water molecules, showing how atoms share electrons to achieve stability. Viewers are encouraged to comment if they wish to see more content on double and triple bonds.

Takeaways

• 🧪 Covalent bonding is defined as the sharing of electrons between atoms to form molecules or compounds.
• 🔬 Covalent bonds occur between two non-metals, while ionic bonds occur between a metal and a non-metal.
• 📉 A quick way to identify covalent bonds in Lewis Dot Diagrams is the absence of brackets and charges, unlike ionic bonds.
• ⚛️ Lewis Dot Diagrams visually represent how atoms bond, showing how they share or transfer electrons, especially focusing on valence electrons.
• 🧮 Valence electrons are the electrons in the outer energy levels of atoms and are involved in bonding.
• 📝 The number of valence electrons can be easily identified by looking at the group numbers on the periodic table.
• 🌍 In covalent bonding, atoms share electrons to become stable and achieve a noble gas configuration (8 electrons in the outer shell, or 2 for hydrogen).
• 💡 Oxygen, with six valence electrons, needs two more to become stable, while hydrogen needs one more to fill its valence shell.
• 🔗 Covalent bonds in molecules like H2 (hydrogen gas), Cl2 (chlorine gas), and H2O (water) involve sharing of electrons to make both atoms stable.
• ⚠️ Lone pairs refer to pairs of electrons that are not involved in bonding, which are present in molecules like water.

Q & A

What is covalent bonding?

Covalent bonding is the sharing of electrons between atoms to form molecules or compounds.

Between what types of atoms does covalent bonding occur?

Covalent bonding occurs between non-metal atoms.

How can you visually distinguish between covalent and ionic bonds in Lewis Dot diagrams?

Covalent bonds do not show brackets or charges in Lewis Dot diagrams, while ionic bonds do.

What are valence electrons, and why are they important in bonding?

Valence electrons are the electrons in the outermost energy level of an atom. They are important because they participate in chemical bonding.

How can you determine the number of valence electrons for an element using the periodic table?

The number of valence electrons for an element can be determined by looking at the Roman group numerals on the periodic table.

Why do atoms in covalent bonds share electrons?

Atoms share electrons in covalent bonds to achieve stability, aiming for a full outer energy level, similar to a noble gas configuration.

How many valence electrons does oxygen have, and how does this affect its bonding?

Oxygen has six valence electrons, meaning it needs two more electrons to achieve a stable configuration. This leads oxygen to form bonds by sharing electrons with other atoms.

What is the significance of lone pairs in a Lewis Dot diagram?

Lone pairs are pairs of electrons that are not shared in bonding. They remain on the atom and affect the shape and reactivity of the molecule.

How do hydrogen atoms achieve stability in a covalent bond?

Hydrogen atoms achieve stability by sharing one electron with another hydrogen atom, resulting in each hydrogen having two electrons in total.

What is the difference between a single bond, double bond, and triple bond in covalent bonding?

A single bond involves one pair of shared electrons, a double bond involves two pairs of shared electrons, and a triple bond involves three pairs of shared electrons.

Outlines

00:00

🧪 Covalent Bonding Basics

In this segment, Miss Martins introduces the concept of covalent bonding, emphasizing that it occurs between non-metal atoms. She explains how to identify metals and non-metals on the periodic table and how to distinguish between covalent and ionic bonds using Lewis Dot diagrams. The absence of brackets and charges in Lewis diagrams indicates covalent bonds, while the presence signifies ionic bonds. She also discusses the role of valence electrons in bonding, explaining how they are represented in Lewis Dot diagrams and how to determine the number of valence electrons using the periodic table or Aufbau diagrams. The segment ends with an example of how to draw Lewis Dot diagrams for elements like oxygen, sodium, and chlorine.

05:02

🌐 Drawing Lewis Dot Diagrams for Covalent Bonds

This paragraph delves into the process of creating Lewis Dot diagrams for covalent bonds, using hydrogen (H2), chlorine (Cl2), and hydrochloric acid (HCl) as examples. Miss Martins explains how to determine the type of bond by considering the elements involved and their positions on the periodic table. She then demonstrates how to represent the valence electrons of each atom and how they share electrons to achieve stability. The process involves counting the valence electrons, identifying the need for additional electrons to reach a stable configuration, and then showing how these electrons are shared between atoms to form single bonds. The segment also includes a brief overview of how to represent lone pairs in Lewis diagrams.

10:04

💧 Covalent Bonding in Water

The final paragraph focuses on the covalent bonding in water (H2O). Miss Martins explains that water is a covalent compound because it involves non-metals (hydrogen and oxygen). She details the process of drawing the Lewis Dot diagram for water, starting with the representation of valence electrons for each hydrogen and the oxygen atom. She then illustrates how hydrogen shares its single electron with oxygen, which in turn shares two of its six electrons with the hydrogen atoms, forming two single bonds. The remaining four electrons on oxygen form two lone pairs. This explanation highlights the concept of single bonds and lone pairs in Lewis Dot diagrams, providing a clear visual of how the water molecule's structure is represented.

📈 Further Exploration of Chemical Bonds

In the concluding remarks, Miss Martins invites viewers to engage with the content by liking, subscribing, and commenting if they are interested in learning more about double and triple bonds. She summarizes the key points covered in the video and encourages viewers to continue their exploration of chemical bonding.

Keywords

💡Covalent bonding

Covalent bonding is defined as the sharing of electrons between atoms to form molecules or compounds. It occurs between non-metal atoms and is key to understanding how certain elements bond. In the video, the example of water (H2O) illustrates covalent bonding, where hydrogen and oxygen share electrons to stabilize their outer energy levels.

💡Non-metals

Non-metals are elements on the periodic table that form covalent bonds by sharing electrons. In the video, the teacher emphasizes that covalent bonding occurs specifically between non-metals, such as hydrogen and oxygen in water. Non-metals can be identified by their position on the periodic table, located to the right of the dividing line between metals and non-metals.

💡Periodic table

The periodic table is a chart that organizes elements based on their atomic structure and properties. In the video, the teacher refers to it to explain how to differentiate between metals and non-metals and how to determine the number of valence electrons, which is crucial for drawing Lewis Dot Diagrams.

💡Valence electrons

Valence electrons are the outermost electrons of an atom that are involved in bonding. The teacher explains that valence electrons determine how atoms bond and are the focus when drawing Lewis Dot Diagrams. For example, oxygen has six valence electrons, which explains its bonding behavior with other atoms.

💡Lewis Dot Diagrams

Lewis Dot Diagrams are visual representations of atoms and their bonding through valence electrons. In the video, the teacher uses these diagrams to show how electrons are shared in covalent bonds or transferred in ionic bonds. The example of water (H2O) illustrates how to draw shared pairs of electrons.

💡Single bond

A single bond occurs when two atoms share one pair of electrons. In the video, this concept is demonstrated with hydrogen (H2), where two hydrogen atoms share one pair of electrons to form a single bond, resulting in a stable diatomic molecule. This is also seen in chlorine (Cl2) and water (H2O).

💡Diatomic molecules

Diatomic molecules are molecules composed of two atoms of the same element, such as H2 or Cl2. The video explains that hydrogen and chlorine form diatomic molecules through covalent bonding, where they share electrons to stabilize their valence shells. Diatomic molecules are common examples in basic chemical bonding.

💡Lone pairs

Lone pairs are pairs of valence electrons that are not involved in bonding and remain on an atom. In the video, the teacher mentions lone pairs when explaining the structure of the water molecule (H2O), where oxygen has two lone pairs of electrons that do not participate in bonding with hydrogen.

💡Noble gas structure

The noble gas structure refers to the stable electron configuration that atoms aim to achieve by bonding, often characterized by having eight valence electrons. In the video, the teacher explains that atoms share or transfer electrons to achieve this stable configuration, as seen in hydrogen bonding to form H2 and oxygen bonding in H2O.

💡Hydrogen molecule (H2)

The hydrogen molecule (H2) is used as an example of covalent bonding in the video, where two hydrogen atoms share one electron each to form a stable bond. This demonstrates how covalent bonds allow atoms to fulfill their need for stability, as hydrogen requires two electrons to complete its valence shell.

Highlights

Introduction to covalent bonding: the sharing of electrons between atoms to form molecules or compounds.

Covalent bonding occurs between two non-metal atoms.

Key difference between covalent and ionic bonds: covalent bonds do not show brackets or charges in Lewis Dot diagrams.

Visualizing bonds: Lewis Dot diagrams help represent how atoms share or transfer electrons.

Valence electrons: the electrons in the outer energy levels of an atom involved in bonding.

Periodic table hack: the group number helps determine the number of valence electrons an atom has.

Drawing Lewis Dot diagrams: each valence electron is represented as a dot or cross around the atomic symbol.

Hydrogen only needs 2 electrons to be stable due to its single orbital, unlike most atoms that need 8.

Single bond formation: when two atoms share one pair of electrons.

Hydrogen molecule (H2) example: two hydrogen atoms share electrons to complete their outer shells.

Chlorine molecule (Cl2) example: each chlorine atom shares one electron to form a covalent bond.

Hydrochloric acid (HCl) example: hydrogen shares its electron with chlorine to stabilize both atoms.

Water molecule (H2O) example: oxygen shares electrons with two hydrogen atoms, forming two single bonds.

Lone pairs: unshared pairs of electrons that remain on the oxygen atom in water.

Call to action: Thumbs up and comments for more videos on double and triple bonds.

Transcripts

hello everyone and welcome to another

video with me Miss Martins and today

we're going to continue with chemical

bonding we're going to be focusing on

covalent bonding in the last lesson we

introduced chemical bonding and we

looked at the three different types if

you missed that lesson I'm going to link

it over here so you want to watch that

one first but today we're going to focus

on covalent bonding which we defined as

the shearing of electrons between atoms

to form molecules or compounds

it's very important to take note that

covalent bonding takes place between a

non-metal and a non-metal now how do I

know which atoms are metals or

non-metals

remember there's a dividing line on the

periodic table that separates Metals

which can be seen over here on this side

of the periodic table with non-metals

which can be seen on this side of the

periodic table just remember that little

hydrogen over here is actually a

non-metal if you get the Lewis Dot

diagrams of different molecules or

compounds the quickest way to see if

it's representing a covalent bond or an

ionic bond is with the absence or the

presence of brackets so what I mean by

that is you can see here in covalent

bonding this is water the hydrogen and

the oxygen are bonded covalently which

means they share electrons you do not

see brackets there you do not see

charges there over here ionic bonds you

can see brackets we can see charges this

is different this is ionic bonding we'll

get to ionic bonding in another video if

you want to see it just let me know down

below but that's just a quick visual way

to tell the difference between a Lewis

Dot Diagram that is representing

covalent bonding versus a Lewis Dot

Diagram that is representing ionic

bonding I keep going on about Lewis Dot

diagrams but what the heck are those

basically Lewis Dot diagrams are a

visual representation of how atoms bond

with one another it shows how they share

electrons if they have a covalent bond

or how electrons are transferred if we

are talking about an ionic bond and

Lewis Dot diagrams always works with the

valence electrons valence electrons are

the electrons found in the outer energy

levels of an atom a very quick way to

tell the number of valence electrons

that an atom has if you look at your

periodic table is to look at the Roman

group numerals that is located here on

your periodic table so for example you

can see here to my right boron has three

valence electrons remember we can also

look at an awful diagram in order to

tell how many valence electrons an atom

has so if you draw the off-bar diagram

for oxygen again if you don't know how

to do this or if you're looking for a

recap on off-bar diagrams I'll link my

video on Alpha diagrams over here we

will see that the outer energy level

which is energy level 2 is not full

energy level 2 has 1 2 3 4 5 6 electrons

because these are the electrons in the

outer energy level we also call them

valence electrons and those are the

electrons that are going to be involved

in bonding so it's the valence electrons

that we draw in our Lewis Dot diagrams

so if I ask you to draw the Lewis Dot

diagrams for the following elements so

not compounds just elements this is how

it works for oxygen what we'll do is

we'll either use an off-bar diagram or

we'll look at our periodic table in

order to see that oxygen has six valence

electrons we draw six dots or six

crosses around oxygen we draw one on

each side so what I mean by that is we

go one two three four let me start at

the top again five and six in total an

atom has space for eight okay which

means that oxygen has an open space over

here and an open space over here it

needs eight electrons in its outer

orbital in its outer energy level in

order to be full but it doesn't have it

it only has six so if I want to do

sodium

we look at sodium on the periodic table

sodium is in group one it's over here we

know that that means that it has one

valence electron it'll have one dot or

cross it doesn't matter where you draw

it I'm just going to do it on the right

hand side so one dot or one cross let's

look at chlorine

chlorine is over here

and as we can see chlorine has seven

valence electrons that you start this

time one two three four five six seven

remember it has space for eight so he

has an open little Gap over here but

chlorine only has seven the reason they

share the electrons is to be stable they

want to reach that noble gas structure

they want to be stable and this is very

important you need to know this hydrogen

needs two in total to be full or stable

hydrogen and helium they only have a 1s

orbital so then they need two electrons

in total to be full or stable

everything else needs eight so if I ask

you to draw a Lewis Dot Diagram for the

hydrogen molecule or H2 or hydrogen gas

this is how you do it you first decide

whether it is an ionic or a covalent

bond it's very obvious that it is a

covalent bond because hydrogen is a

non-metal so a hydrogen and a hydrogen

will be two non-metals then what we do

is we think about the valence electrons

that each hydrogen atom has so one eye

this hydrogen atom has one electron

this hydrogen atom has one electron

because I have two hydrogen atoms I'm

going to use an X to represent the

electron in the first hydrogen atom and

adopt to represent the one valence

electron in the second then we think

about the following we said hydrogen

needs two in order to be full

each hydrogen only has one so what they

do is these hydrogen atoms share those

electrons with each other so we add

these together and my final compound you

draw them closer to each other and you

draw the shared electrons in the middle

now each hydrogen has two electrons so

this hydrogen on the left has two

electrons this hydrogen on the right has

two electrons and remember hydrogen only

needs two to be stable to fill its outer

energy levels so that is a single Bond

because they share one pair of electrons

this is why hydrogen is diatomic if we

look at chlorine or the chlorine

molecule cl2 again we know that this is

covalent bonding because chlorine is a

non-metal so we have a chlorine atom

with a chlorine atom two non-metals each

chlorine look at the number of valence

electrons each chlorine has seven

valence electrons so it has space for

one more remember it needs eight to be

stable

the second chlorine molecule also has

seven so one two three four five six

seven again another space it needs one

more electron to be full so think about

it they each have seven

they each need one more to be full so

these electrons over here these two over

here can be shared with one another

green electrons that are highlighted

they're going to pull to the middle

because they're going to be shared and

then you just fill in the other

electrons as normal this pair of

electrons over here you see it's a pair

which means it's a single Bond if they

share one pair of electrons they form a

single Bond and again here's a little

quick summary of the chlorine molecule

look at HCL or hydrochloric acid we know

that it is a covalent bond because

hydrogen is a non-metal I know it's on

the left hand side of the periodic table

but remember

hydrogen is an exception it's a

non-metal and chlorine is also a

non-metal hydrogen has one valence

electron you can see there by the Roman

group numeral

chlorine has seven

think about it hydrogen needs two to be

stable chlorine needs eight so hydrogen

needs one more chlorine needs one more

then they think oh cool we can just

share these with each other so you draw

them closer to each other and then the

things that they share

they go to the middle and that becomes

the shared pair of electrons so yeah you

can see one pair of electrons are shared

single Bond here is a nice summary for

you to understand them and then finally

let's do H2O or water again it's

covalent because hydrogen and oxygen are

non-metal so non-metal in a non-metal if

you think about this compound now we've

got one oxygen and two hydrogens so

this hydrogen has one valence electron

the second hydrogen also has one valence

electron plus our oxygen atom let's look

at oxygen oxygen has six valence

electrons now remember hydrogen needs

two to be stable so it has six

it needs two more it needs two more and

isn't it just perfect because it needs

two more it can share this one with that

hydrogen and this one with that hydrogen

and think about it that will also make

the hydrogens full and stable so I'm

going to draw the final molecule

molecule here oxygen will go in the

middle and it makes sense because oxygen

needs to share with this hydrogen and

this hydrogen so I'm going to fill in

everything else as is with oxygen just

like I had it initially

now you see over here I have an open

space that's where the first Hydrogen is

going to come closer and share that

electron in this open space the other

hydrogen is going to come closer and

share that electron now you have to

count the number of electrons around

oxygen you'll get eight and each

hydrogen has two it's basically like

this a single Bond over there and a

single Bond over there how do I know

it's two single bonds because this is a

single pair of electrons that's shared

over there which creates a single Bond

and a single pair of electrons that is

shared over there that creates a single

Bond these two electrons here that is

called a lone pair and we have another

two electrons over there which is

another lone pair another summary for

you and if you would like to see me do

double bonds and triple bonds please

give this video a thumbs up so that I

know you want to see more and comment

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