Introduction to Ionic Bonding and Covalent Bonding
Summary
TLDRThis educational video explores the fundamental differences between ionic and covalent bonds. Ionic bonding involves electron transfer, typically between metals and non-metals, forming ions that attract each other. Covalent bonds, on the other hand, involve electron sharing, with distinctions between polar and nonpolar based on electronegativity differences. The video uses examples like sodium chloride and hydrogen fluoride to illustrate these concepts, providing a clear guide for understanding chemical bonding.
Takeaways
- 🔬 Ionic bonding involves the transfer of electrons from one atom to another, resulting in the formation of ions.
- 📊 Sodium (Na) and chlorine (Cl) are used as examples to illustrate the formation of ionic bonds, with sodium giving up an electron to chlorine.
- 💡 Metals tend to lose electrons and form positive ions, while non-metals tend to gain electrons and form negative ions.
- ⚛️ The electrostatic force of attraction between oppositely charged ions is what forms the ionic bond.
- 🌐 Covalent bonding involves the sharing of electrons between atoms, as opposed to the transfer seen in ionic bonding.
- 🌀 Hydrogen atoms share their single valence electron to achieve a stable electron configuration, exemplifying covalent bonding.
- 🔍 There are two types of covalent bonds: polar and nonpolar, differentiated by the equality of electron sharing.
- 📊 The bond between two hydrogen atoms is nonpolar because the electrons are shared equally.
- 🌐 In polar covalent bonds, there is an unequal sharing of electrons due to differences in electronegativity between the atoms.
- 📈 Electronegativity is a measure of an atom's ability to attract electrons, with fluorine being the most electronegative element.
- 🔑 To determine if a bond is polar or nonpolar covalent, calculate the electronegativity difference; a difference of 0.5 or more indicates a polar covalent bond.
- 📚 The periodic table is a useful tool for identifying likely ionic compounds (metal and non-metal combinations) and for understanding electron configurations.
Q & A
What is the primary difference between ionic and covalent bonding?
-In ionic bonding, electrons are transferred from one element to another, forming ions, while in covalent bonding, electrons are shared between atoms.
Why do metals tend to form positively charged ions?
-Metals, like sodium, tend to form positively charged ions because they like to give away their valence electrons to achieve a stable electron configuration.
How does the valence electron count influence the bonding behavior of elements?
-Elements with one valence electron, like sodium, tend to lose it to form a +1 ion, while elements with seven valence electrons, like chlorine, tend to gain one electron to form a -1 ion.
What is the significance of the periodic table in predicting the type of bonding?
-The periodic table helps in predicting bonding by identifying elements' groups and their valence electrons, which in turn indicates their tendency to form ions or share electrons.
What is the electrostatic force that holds ionic bonds together?
-The electrostatic force that holds ionic bonds together is the attraction between oppositely charged ions, such as a positively charged sodium ion and a negatively charged chloride ion.
Why are hydrogen atoms in the first row of the periodic table different from those in the second row?
-Hydrogen atoms, being in the first row, aim to have two electrons in their outer energy level to achieve stability, unlike second-row elements which aim for eight electrons to satisfy the octet rule.
What is a covalent bond and how does it differ from an ionic bond?
-A covalent bond is formed when two atoms share electrons to achieve a stable electron configuration, unlike ionic bonds which involve the transfer of electrons and the formation of ions.
What determines whether a covalent bond is polar or nonpolar?
-A covalent bond is polar if there is an unequal sharing of electrons due to a difference in electronegativity between the atoms, and nonpolar if the electrons are shared equally.
How can you identify a polar covalent bond?
-A polar covalent bond can be identified by calculating the difference in electronegativity between the bonded atoms; if the difference is 0.5 or more, the bond is considered polar.
What is electronegativity and how does it affect bond polarity?
-Electronegativity is the ability of an atom to attract electrons towards itself. A higher electronegativity difference between bonded atoms results in a polar covalent bond due to the unequal sharing of electrons.
Can you provide an example of a nonpolar covalent bond?
-An example of a nonpolar covalent bond is the bond between two hydrogen atoms, where the electrons are shared equally due to the identical electronegativity of both atoms.
How does the presence of hydrogen bonds affect the polarity of a bond?
-Hydrogen bonds, such as those formed between hydrogen and oxygen, nitrogen, or fluorine, are inherently polar due to the significant electronegativity difference between hydrogen and the other atom, resulting in an unequal distribution of electron density.
What is the general rule for identifying ionic compounds?
-Ionic compounds are generally formed between metals and nonmetals, where metals tend to lose electrons to form positive ions and nonmetals tend to gain electrons to form negative ions.
Outlines
🔬 Ionic and Covalent Bonding Basics
This paragraph introduces the fundamental concepts of ionic and covalent bonding. Ionic bonding occurs when electrons are transferred from one atom to another, resulting in the formation of ions. An example is the reaction between sodium (a metal from Group 1A) and chlorine (a halogen from Group 7A), where sodium donates its valence electron to chlorine, forming positively charged sodium ions and negatively charged chloride ions. These ions are attracted to each other due to the electrostatic forces between opposite charges, leading to the formation of an ionic bond. The paragraph also contrasts this with covalent bonding, where electrons are shared between atoms, using hydrogen as an example of an element that shares electrons to achieve a stable electron configuration.
🔍 Distinguishing Polar and Nonpolar Covalent Bonds
The second paragraph delves into the specifics of covalent bonding, explaining the difference between polar and nonpolar covalent bonds. It uses the example of a bond between two hydrogen atoms, which is nonpolar because the electrons are shared equally. In contrast, a bond between hydrogen and fluorine is polar because fluorine, being more electronegative, pulls the electrons towards itself, creating a partial negative charge on fluorine and a partial positive charge on hydrogen. This results in a polar molecule with an unequal distribution of charge, or a dipole. The concept of electronegativity, the ability of an atom to attract electrons, is also introduced, with fluorine being highlighted as having a high electronegativity value.
📚 Classifying Chemical Bonds with Examples
The final paragraph provides a practical approach to classifying chemical bonds as ionic, polar covalent, or non-polar covalent. It suggests looking for the presence of a metal and a non-metal to identify ionic compounds, such as magnesium oxide (MgO). For covalent bonds, it discusses the importance of electronegativity differences, with a difference of 0.5 or more indicating a polar covalent bond, as illustrated with hydrogen bromide (HBr). The paragraph also touches on special cases like hydrogen bonds and provides a method to determine the polarity of bonds involving carbon, hydrogen, oxygen, and other elements. It concludes with the assertion that understanding these concepts is essential for grasping the nature of chemical bonding.
Mindmap
Keywords
💡Ionic Bonding
💡Covalent Bonding
💡Electron Transfer
💡Valence Electrons
💡Electronegativity
💡Polar Covalent Bond
💡Nonpolar Covalent Bond
💡Dipole
💡Octet Rule
💡Metal and Nonmetal
💡Hydrogen Bond
Highlights
The video discusses the fundamental differences between ionic and covalent bonding.
In ionic bonding, electrons are transferred from one element to another, forming ions.
Sodium and chlorine atoms are used as an example to illustrate the formation of ionic bonds.
Sodium, being an alkali metal, tends to lose its valence electron to form a positively charged ion.
Chlorine, a halogen, gains an electron to form a negatively charged anion due to its high reactivity.
The electrostatic force between oppositely charged ions creates an ionic bond.
Covalent bonds involve the sharing of electrons between atoms, as demonstrated with hydrogen atoms.
Hydrogen atoms share electrons to achieve a stable electron configuration with two electrons in their outer shell.
Covalent bonds are categorized into polar and nonpolar based on the sharing of electrons.
A nonpolar covalent bond, like the one between two hydrogen atoms, involves equal sharing of electrons.
Polar covalent bonds result from unequal electron sharing due to differences in electronegativity between atoms.
Electronegativity is the measure of an atom's ability to attract electrons, with fluorine being the most electronegative element.
The video provides a method to determine the polarity of covalent bonds using electronegativity differences.
An electronegativity difference of 0.5 or more indicates a polar covalent bond.
Examples of different types of bonds are given, including magnesium oxide (ionic), chlorine atoms (nonpolar covalent), and sodium fluoride (ionic).
Hydrogen bromide (HBr) is identified as a polar covalent bond due to a significant electronegativity difference.
Iodine monobromide is classified as a relatively nonpolar covalent bond based on a smaller electronegativity difference.
Carbon-hydrogen bonds are memorably nonpolar due to a small electronegativity difference.
Hydrogen bonds, such as the OH bond, are inherently polar due to the high electronegativity of oxygen.
The video concludes with a summary of the key differences between ionic and covalent bonds.
Transcripts
in this video we're going to discuss the
difference between ionic and covalent
bonding
in ionic bonding
electrons are transferred from one
element to another and typically ionic
bonds contain ions
in a covalent bond electrons are shared
but let's go over ionic bonding first
let's consider the reaction between an
atom of sodium and an atom of chlorine
sodium
as an atom has one valence electron
if you look where it is in the periodic
table it's in the first column it's in
group 1a
of the periodic table and elements in
that group all contain one valence
electron
a valence electron is simply the
electrons in the last
or outermost energy level
chlorine which is a halogen
contains
seven valence electrons it's in group 7a
of the periodic table
the halogens are very reactive
non-metals
and the alkali metals where sodium is
found
are very reactive metals metals like to
give away electrons and so they form
positively charged ions
non-metals they like to receive
electrons
and so they form negatively charged
anions
so sodium
is going to give chlorine
one of its electron or valence electron
since it only has one
so as sodium loses that one valence
electron
it's going to acquire a positive charge
and as chlorine gains
that electron
it requires a negative charge
now going back to physics
if you have two like charges next to
each other what's going to happen
like charges repel
they're going to feel an electric force
that repels them or pushes them away
from each other
but what's going to happen if you have a
positive
and a negative charge
next to each other
these two are attracted to each other
they feel a force of attraction that
pulls them together
and so that's what's happening between
the sodium ion and the chloride ion
the sodium ion which now has a net
positive charge is attracted to the
chloride ion which has a negative charge
and so these two they feel a force of
attraction
and that force of attraction that
electrostatic force
it binds them together and so that
creates the ionic bond
so keep this in mind
within ionic bonds you have a transfer
of electrons
and the bonds that hold them
are as a result of the electrostatic
forces between
opposite charges keep in mind opposite
charges attract each other
so now let's move on into covalent
bonding
let's look at hydrogen
a hydrogen atom has one valence electron
and
it's in the first row of the periodic
table
elements in the first row
they want to have a total of two
electrons in their outer energy level
the second row elements they want to
have eight electrons
so elements like oxygen fluorine they
want to satisfy their octet they want to
have eight electrons but hydrogen and
helium they can only have two electrons
in their first shell
so each of these hydrogens they need one
more electron to fill that first shell
with a total of two electrons
and both of these elements are the same
so what they're going to do is they're
going to share
their electrons
and so these two they're going to form a
bond
so when you see a bond this bond
represents the sharing of two
electrons and so this is a covalent bond
anytime you have sharing of electrons
it's a covalent bond
now there's two types of covalent bonds
you need to be familiar with
polar covalent bonds
and nonpolar covalent bonds
the bond between two hydrogen atoms is
considered to be a nonpolar covalent
bond the reason why it's nonpolar is
because the electrons are shared equally
between those two hydrogen atoms
now if you look at the bond between
hydrogen and fluorine
the elements are different
fluorine is much more electronegative
than hydrogen
because fluorine is electronegative
it's going to pull the electrons toward
itself
now granted
the electrons are still being shared but
they're being shared unequally
and whenever you have an unequal sharing
of electrons
you have a polar
covalent bond
as opposed to
a nonpolar
covalent bond
so because fluorine is more
electronegative
as it pulls the electrons toward itself
fluorine is going to acquire a partial
negative charge and hydrogen is going to
be partially positive
and whenever you have an object where
one side is positive and the other side
is negative
you have a dipole you have a polarized
object
and this is what it means to be polar
you have
an unequal distribution of
charge one side is positive one side is
negative so the electrons they're not
distributed evenly
in that molecule
the electrons spend more time closer to
fluorine because it's more
electronegative
electronegativity is the ability of an
atom
to
attract an electron toward itself and
fluorine it does a good job in doing
that
so now you know what a polar covalent
bond is
it's a bond where you have unequal
strand of electrons and a non-polar
covalent bond is a bond where you have
equal sharing of electrons
now let's go over some practice problems
i want you to classify
the following bonds
as being ionic
polar covalent or non-polar covalent
so let's start with the first one
mgo
magnesium oxide
is it ionic polar covalent or non-polar
covalent
the first thing i would look for is to
see if it's ionic
typically
an ionic compound consists of a metal
and a non-metal that's how you can
easily identify it
magnesium is a metal
metals exist on the left side of the
periodic table
nonmetals exist on the right side the
nonmetals are on the upper right side
the metals are on the lower left side
so magnesium
is a metal
and oxygen which is on the upper right
side of the periodic table that's a
nominal
so this is going to be ionic
magnesium
forms a plus two
charge as an ion
it has two valence electrons so in this
bond
it's going to give away two electrons to
oxygen
oxygen
which is a calcagen
magnesium is an alkaline earth metal
but oxygen
it has six valence electrons it needs
two more to get to eight so once it
acquires those two electrons it's going
to have a negative charge as you can see
this compound is composed of ions
now what about two chlorine atoms
chlorine is a nominal whenever you have
two nonmetals with the same type of
element
it's always going to be a nonpolar
covalent
the electrons are shared equally
because we have the same type of atom
now what about sodium fluoride
sodium is on the left side of the
periodic table so it's a metal
and fluorine is a halogen on the right
side so that's a non-metal so sodium
fluoride contains ionic bonding
now what about hbr
is it polar covalent
or nonpolar covalent
now the elements are different so that
could be an indication that it might be
polar covalent but you need to run a
test
you need to calculate the difference in
electronegativity
if the electronegativity difference
is equal to or greater than 0.5
most textbooks they use this number
if it's 0.5 or more then the bond is
considered to be polar covalent
if it's less than 0.5 if it's 0.4 or
less
then it's considered to be non-polar
covalent
so if you need the electronegativity
values you can go to google images
and type in
electronegativity table and you'll see
some tables come up
now i've seen different tables with
different values they don't very much
but sometimes they do vary
so if you're doing a homework problem
use whatever table your book gives you
in the table that i use
hydrogen
has an electronegativity value of 2.1
bromine it's about 2.8
and so the en difference
is 0.7
therefore this is going to be
polar
covalent i'm going to write pc for polar
covalent
now what about
iodine
monobromide
what is the difference in
electronegativity
iodine has
an electronegativity value of 2.5 and
for bromine 2.8
so the en difference
is about 0.3
which means that it's relatively
non-polar covalent so i'm going to write
unseen again make sure you use the table
that your book provides because if the
values are slightly different
the result might be different
but the idea is that you want to find
an ian difference of 0.5 or more to see
if it's polar or not
so let's try some more examples
determine if the following bonds
is polar covalent
non-polar covalent or ionic
so let's look at carbon and hydrogen
has an electronegativity value of 2.5
and for hydrogen is 2.1
so the en difference is 0.4
for this one i would commit this memory
anytime you see carbon hydrogen it's
going to be nonpolar
this is a very common example that
you'll see within chemistry and even
organic chemistry
now what about the oh bond
whenever hydrogen is bonded to oxygen
nitrogen or fluorine you have a special
case of bonding known as hydrogen bonds
whenever you have hydrogen bonds it's
going to be polar by the way
oxygen has an electronegativity value of
3.5
so 3.5 minus 2.1 the difference is huge
so 1.4 this bond is very polar
so this is polar covalent
this is non-polar covalent
now if the two atoms are the same and
they're both not metals
it's going to be non-polar covalent you
don't really need to do the calculation
fluorine has an electronegativity value
of 4.0 4 minus 4 is 0 which is less than
0.5
now calcium sulfide
for this you really don't need the
electronegativity values you just need
to know that calcium is a metal
and sulfur is a nominal
and then so you could say it's ionic
if you have one element all the way to
the left side of the periodic table and
another all the way to the right side
it's going to be ionic
so that is it for this video now you
understand the difference between ionic
and covalent bonding so thanks for
watching and have a great day
تصفح المزيد من مقاطع الفيديو ذات الصلة
INTRAMOLECULAR BONDING - COVALENT, IONIC, METALLIC
Covalent Compounds VS Ionic Compounds
Chemical Bonding Explained | Ionic, Covalent and Metallic | GCSE Chemistry
Chemical Bonding | Ionic and Covalent | Grade 9 Science Quarter 2 Week 2
CHEM 257 - Fall 2024 - Lecture 1 - Video 2
Ligações químicas: tipos e características
5.0 / 5 (0 votes)