Introduction to Chemical Bonding & Lewis Theory of Chemical Bonding Video Lecture | Chemistry for JEE Main & Advanced

0:0:0: just imagine for a moment
0:0:2: a world where everything around you is
0:0:5: made up of individual atoms with no
0:0:7: chemical bonds holding them together
0:0:10: can you even begin to imagine what the
0:0:12: air you breathe or the ground you walk
0:0:14: on would look like in such a world
0:0:17: it's a difficult concept to grasp but
0:0:19: fortunately that is not the world we
0:0:22: inhabit
0:0:23: our reality is composed of various types
0:0:26: of atoms that unite to form molecules
0:0:28: and these molecules then join forces to
0:0:31: create compounds
0:0:33: however have you ever pondered the
0:0:35: question of why and how these atoms and
0:0:37: molecules bond together
0:0:40: this is a question that has confounded
0:0:42: scientists for centuries and remains one
0:0:44: of the most profound mysteries of our
0:0:46: universe
0:0:48: are you ready to uncover the secrets of
0:0:50: chemical bonding
0:0:52: in this class 11 video we will explore
0:0:54: the captivating world of chemical bonds
0:0:57: and delve into the fundamental process
0:0:59: by which atoms molecules or ions come
0:1:2: together to form a stable chemical
0:1:4: compound
0:1:5: there are several theories that explain
0:1:7: the nature of chemical bonds including
0:1:10: the causal Lewis approach valence shell
0:1:12: electron pair repulsion Theory the
0:1:14: valence Bond Theory and the molecular
0:1:17: orbital Theory
0:1:19: in this video we will delve deeper into
0:1:21: what is chemical bonding and why
0:1:23: chemical bonding occurs to form
0:1:25: compounds
0:1:26: specifically we will also focus on the
0:1:29: parcel Lewis approach also known as the
0:1:31: Lewis theory of chemical bonding which
0:1:34: was one of the earliest and most
0:1:35: influential theories
0:1:38: we will cover essential Concepts under
0:1:40: the castle Lewis approach such as the
0:1:42: octet rule Lewis symbols and more
0:1:46: get ready to uncover the secrets of
0:1:48: chemical bonding in this exciting video
0:1:51: so what exactly is chemical bonding
0:1:54: chemical bonding is a fundamental
0:1:57: process by which atoms molecules or ions
0:2:0: come together to form a stable chemical
0:2:2: compound
0:2:3: atoms as you know are composed of three
0:2:6: types of particles positively charged
0:2:9: protons neutral neutrons and negatively
0:2:12: charged electrons that orbit around the
0:2:15: nucleus
0:2:16: the electrons in the outermost shell of
0:2:19: an atom call valence electrons are
0:2:21: primarily responsible for the formation
0:2:24: of chemical bonds
0:2:25: in order to achieve stability atoms seek
0:2:28: to either gain lose or share electrons
0:2:32: when atoms come close to each other the
0:2:35: electrons in their valence shells
0:2:36: interact with each other leading to the
0:2:39: formation of a chemical bond
0:2:41: overall chemical bonding plays a
0:2:43: critical role in the formation of matter
0:2:45: in the universe as it enables the
0:2:48: creation of countless chemical compounds
0:2:50: with a vast range of properties and
0:2:52: applications
0:2:54: now let's explore the question why
0:2:57: chemical bonding occurs to form
0:2:58: compounds
0:3:0: chemical bonding occurs to form
0:3:2: compounds due to two main reasons the
0:3:5: tendency to acquire minimum energy and
0:3:7: the tendency to acquire noble gas
0:3:9: configuration
0:3:11: let us discuss them one by one
0:3:14: first reason of chemical bond formation
0:3:16: is tendency to acquire minimum energy
0:3:20: as we know the behavior of charged
0:3:22: particles plays an important role in the
0:3:25: formation of chemical bonds
0:3:27: unlike charges such as a positive and
0:3:30: negative charge are attracted to each
0:3:32: other whereas like charges such as to
0:3:35: positive or to negative charges repel
0:3:38: each other
0:3:39: a similar phenomenon occurs when two
0:3:41: atoms approach each other to form a bond
0:3:44: when two atoms come close to each other
0:3:47: the positively charged nucleus of one
0:3:50: atom attracts the negatively charged
0:3:52: electrons of the other atom
0:3:54: however the negatively charged electrons
0:3:57: of one atom repel the negatively charged
0:4:0: electrons of the other atom
0:4:2: this results in a combination of
0:4:4: Attraction and repulsion forces acting
0:4:7: between the two atoms
0:4:9: according to the principles of quantum
0:4:11: theory these opposing forces create a
0:4:13: balance at a certain minimum distance
0:4:15: which is known as the bond formation
0:4:18: condition or equilibrium state
0:4:21: the atoms of elements become stable by
0:4:23: forming bonds which lowers their energy
0:4:27: if the net result of the attraction and
0:4:29: repulsion forces is attraction then the
0:4:31: total energy of the system decreases and
0:4:34: a chemical bond forms
0:4:36: however if the net result is repulsion
0:4:39: then no chemical bonding is possible
0:4:42: so chemical bonding is a phenomenon that
0:4:45: occurs in order for atoms to form
0:4:47: compounds and achieve a lower and
0:4:49: stabilized energy state
0:4:51: the second reason of chemical bond
0:4:54: formation is tendency to acquire noble
0:4:56: gas configuration
0:4:58: in addition to the tendency to achieve a
0:5:0: minimum energy State chemical bonding is
0:5:3: also driven by the desire to attain a
0:5:5: noble gas configuration
0:5:8: elements in the inert gas group such as
0:5:10: helium neon and argon have stable
0:5:13: electronic configurations and are not
0:5:16: chemically reactive
0:5:18: atoms of other elements combine with
0:5:20: each other to achieve the same stable
0:5:22: electronic configuration as the inert
0:5:24: gases
0:5:26: the most stable configuration is to have
0:5:28: either two electrons in the case of the
0:5:31: First Energy shell or eight electrons in
0:5:34: their outermost energy level
0:5:36: this configuration is called the octet
0:5:38: rule and it is a state of Maximum
0:5:41: stability and minimum energy
0:5:43: only the electrons in the outermost
0:5:45: energy shell which are known as valence
0:5:48: electrons participate in the bond
0:5:50: formation
0:5:52: these include the NS NP and N minus 1 D
0:5:56: orbitals
0:5:58: therefore atoms combine to attain a
0:6:0: stable electronic configuration and
0:6:3: lower their energy which leads to the
0:6:5: formation of chemical compounds
0:6:7: this desire to achieve noble gas
0:6:9: configuration is a fundamental driving
0:6:12: force behind many chemical reactions and
0:6:14: the basis for the octet rule which is a
0:6:17: topic we will be discussing in detail
0:6:19: later in the video
0:6:21: up until this point we have covered the
0:6:24: definition of chemical bonding and the
0:6:26: reasons behind its occurrence in
0:6:27: compound formation
0:6:29: moving forward we will delve into the
0:6:32: initial theory of chemical bonding also
0:6:34: known as the Lewis theory of causalaves
0:6:37: approach
0:6:38: what exactly is the Lewis theory of
0:6:40: chemical bonding or causality's approach
0:6:43: the causal levels approach also known as
0:6:46: the Lewis theory of chemical bonding is
0:6:49: a fundamental and influential theory of
0:6:51: chemical bonding proposed by American
0:6:53: chemist Gilbert and Lewis in 1916 and
0:6:57: later refined by German physicist Walder
0:6:59: cossel
0:7:0: the theory explains how elements combine
0:7:3: to form compounds and molecules and what
0:7:6: makes chemical bonds so strong
0:7:8: according to Lewis Theory atoms consist
0:7:11: of a positively charged kernel and an
0:7:14: outer shell that holds the valence
0:7:15: electrons
0:7:17: atoms are considered most stable when
0:7:19: their outer shell is filled with eight
0:7:21: electrons which is called the octet
0:7:23: configuration
0:7:25: achieving this table configuration is
0:7:27: crucial for atoms as it symbolize
0:7:30: stability
0:7:31: atoms can achieve this stable
0:7:33: configuration by forming chemical bonds
0:7:35: with other atoms following the octet
0:7:38: rule
0:7:39: the octet rule proposed by the kosalev's
0:7:42: approach is a fundamental principle in
0:7:44: chemistry that states that atoms tend to
0:7:46: gain lose or share electrons to achieve
0:7:50: a stable configuration of eight valence
0:7:52: electrons in their outermost shell
0:7:55: this principle applies to most elements
0:7:58: in the periodic table Except for
0:8:0: hydrogen and helium which only require
0:8:2: two electrons to achieve stability
0:8:6: the Lewis theory of chemical bonding
0:8:8: visualize the sharing and transfer of
0:8:10: electrons to achieve the stable
0:8:12: configuration of eight electrons in the
0:8:14: outer shell
0:8:16: during chemical bonding atoms gain lose
0:8:19: or share electrons and become stable
0:8:22: in an ionic bond atoms transfer
0:8:25: electrons and become ions
0:8:28: the octet rule can explain the formation
0:8:30: of sodium chloride through electron
0:8:32: transfer resulting in an ionic bond
0:8:35: sodium has one electron in its valence
0:8:38: shell
0:8:39: it will lose the electron and become
0:8:42: sodium ion
0:8:43: chlorine has seven electrons in its
0:8:46: valence shell
0:8:47: it will accept the electron from sodium
0:8:50: will transform itself to chloride ion
0:8:53: and take the stable electron
0:8:54: configuration
0:8:56: whereas in covalent bonding atoms share
0:8:59: electrons
0:9:1: covalent bonding in carbon dioxide can
0:9:4: also be explained by the octet rule
0:9:6: which involves the sharing of electrons
0:9:9: specifically carbon has four valence
0:9:12: electrons while oxygen has six
0:9:15: based on the electronegativity
0:9:17: difference between carbon and oxygen we
0:9:20: can predict that the chemical bonding in
0:9:22: carbon dioxide is covalent
0:9:24: as a result carbon and oxygen will share
0:9:27: to valence electrons and form to double
0:9:30: bonds
0:9:31: ultimately both carbon and oxygen will
0:9:34: have eight outermost electrons in carbon
0:9:37: dioxide
0:9:38: after discussing the octet rule of the
0:9:41: causalaves approach in detail let's now
0:9:43: summarize this approach
0:9:45: the causalaves approach also known as
0:9:48: the Lewis theory of chemical bonding or
0:9:50: electronic theory of chemical bonding
0:9:53: proposes that only valence electrons
0:9:55: participate in the formation of chemical
0:9:57: bonds between atoms
0:10:0: in order to achieve a stable octet
0:10:2: configuration atoms will either share or
0:10:5: transfer electrons
0:10:7: I hope you have got a solid
0:10:9: understanding of the causalovies
0:10:10: approach let's dive straight into the
0:10:12: final topic of this video what are Lewis
0:10:15: symbols and how to draw them
0:10:17: Lewis symbols are a type of notation
0:10:19: used to represent the valence electrons
0:10:22: of an atom
0:10:23: they are a simple and effective way of
0:10:25: depicting the outermost electrons of an
0:10:28: atom which are crucial in chemical
0:10:30: bonding
0:10:31: in Lewis symbols the chemical symbol of
0:10:34: the atom is written and the valence
0:10:35: electrons are represented by dots around
0:10:38: the symbol
0:10:39: the number of dots in the Lewis symbol
0:10:41: corresponds to the number of valence
0:10:43: electrons of the atom
0:10:45: by using Lewis symbols chemists can
0:10:48: easily represent and analyze the
0:10:50: electron configurations of atoms and
0:10:53: molecules
0:10:54: for example the Lewis symbol of carbon
0:10:57: depicts a c surrounded by four valence
0:10:59: electrons because carbon has an
0:11:1: electronic configuration of 1s2 2s2 to
0:11:5: P2
0:11:6: electrons that are not in the valence
0:11:8: level are not shown in the Lewis symbol
0:11:11: the reason for this is that the chemical
0:11:13: reactivity of an atom of the element is
0:11:16: solely determined by the number of its
0:11:18: valence electrons and not its inner
0:11:20: electrons
0:11:22: have a look at some examples of Lewis
0:11:24: symbols of different atoms
0:11:26: to draw the Lewis Dot symbol of an
0:11:28: element we must first know how many
0:11:31: valence electrons it has
0:11:33: remember this is easily determined based
0:11:36: on the group number of the elements
0:11:38: since valence electrons are the ones in
0:11:41: the outermost energy shell of the
0:11:43: element
0:11:44: for example oxygen is in group 6 and
0:11:47: therefore it has six valence electrons
0:11:50: and just like this we can draw the Lewis
0:11:53: symbols of all the main group elements
0:11:56: simply add dots one by when to represent
0:11:59: the valence electrons
0:12:1: for instance magnesium is in group 2A so
0:12:5: it has two valence electrons and is
0:12:7: represented by two dots while C is in
0:12:10: group 4A and has 4 valence electrons
0:12:13: represented by four dots
0:12:15: so
0:12:17: this concludes our discussion on Lewis
0:12:19: symbols
0:12:20: I hope you found the information about
0:12:23: chemical bonding important and enjoyable
0:12:25: in this video
0:12:27: looking forward to seeing you in the
0:12:29: next one and now you should start
0:12:32: studying this chapter with the edurev
0:12:34: app as you get with your lectures notes
0:12:36: variety of questions and McQ tests for
0:12:39: all the chapters of each subject
0:12:42: it's like having the entire School in
0:12:44: your pocket