Name: lewis structures with formal charge
Uploaded: 2020-09-03T13:38:28.000Z
Duration: 2 min 42 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Chemistry

Matter and its Interactions

PS.Chm.3.1

Formal Charges

Niektóre cząsteczki lub jony wieloatomowe mogą być reprezentowane przez wiele struktur Lewisa, ale jak zdecydować, która z nich jest dominującą strukturą? 

Obliczając ładunki formalne atomów, można określić strukturę Lewisa najbliższą rzeczywistej strukturze cząsteczki.

Każdemu atomowi przypisany jest hipotetyczny ładunek zwany ładunkiem formalnym, który byłby ładunkiem atomu, gdyby wszystkie inne atomy w cząsteczce miały tę samą elektroujemność. Zakłada ona, że każdy elektron wiążący jest równo współdzielony przez dwa atomy. 

Weźmy pod uwagę chlorowodór. Aby określić ładunek formalny na każdym atomie, najpierw dodaj liczbę elektronów niewiążących do połowy liczby elektronów wiążących, a następnie odejmij uzyskaną wartość od liczby elektronów walencyjnych. 

Suma wszystkich ładunków formalnych w cząsteczce lub jonie jest równa ładunkowi netto cząsteczki lub jonu. 

Na przykład podtlenek azotu może być reprezentowany przez trzy możliwe struktury Lewisa – jedną z dwoma wiązaniami podwójnymi, jedną z potrójnym wiązaniem między atomami azotu i jedną z potrójnym wiązaniem między azotem a tlenem – wszystkie te cechy spełniają oktet. Najlepszą strukturę Lewisa określa się na podstawie formalnych obliczeń ładunku.

Azot ma pięć elektronów walencyjnych, a tlen ma sześć elektronów walencyjnych. Obliczenia oparte na liczbie elektronów niewiążących i połowie liczby elektronów wiążących dają ładunek formalny dla każdej struktury. Ponieważ podtlenek azotu jest cząsteczką obojętną, suma wszystkich ładunków formalnych musi wynosić zero. 

Ogólnie rzecz biorąc, ładunki formalne na poszczególnych atomach w dominującej strukturze Lewisa są najbliższe zeru. W związku z tym można pominąć trzecią strukturę z wyższym zarzutem formalnym. 

Dodatkowo, ujemny ładunek formalny, jeśli jest obecny, powinien być przenoszony przez najbardziej elektroujemny atom. 

Ponieważ tlen jest bardziej elektroujemny niż azot, druga struktura, z ujemnym ładunkiem formalnym tlenu, jest identyfikowana jako dominująca struktura podtlenku azotu. 

Ładunki formalne nie są rzeczywistymi ładunkami cząsteczek czy atomów, ale konwencją księgową. Rzeczywisty ładunek cząsteczki zależy od kilku czynników, w tym od różnicy elektroujemności między atomami składowymi.

Ładunek formalny

W niektórych przypadkach pozornie istnieje więcej niż jedna pasująca struktura Lewisa dla cząsteczek i jonów wieloatomowych. Koncepcję ładunków formalnych można wykorzystać do przewidzenia najodpowiedniejszej struktury Lewisa, gdy istnieje więcej niż jedna rozsądna struktura.

<h4>Obliczanie ładunku formalnego</h4>

Ładunek formalny atomu w cząsteczce to hipotetyczna wartość ładunku, jaką miałby atom, gdyby elektrony w wiązaniach były równomiernie rozmieszczone pomiędzy atomami. Alternatywnie ładunek formalny wynika z tego, że w liczbie elektronów walencyjnych atomu obojętnego najpierw redukuje się elektrony niewiążące, a następnie odejmuje się liczbę wiązań związanych z tym atomem w strukturze Lewisa.

Zatem opłatę formalną oblicza się w następujący sposób:

<img alt="Eq1" src="https://www.jove.com/files/core/CDNSource/lessons/1065/1065_Equations-01.png" style="height: 60px;" />

Obliczenia ładunków formalnych można sprawdzić ponownie, ustalając sumę ładunków formalnych dla całej konstrukcji. Suma ładunków formalnych wszystkich atomów w cząsteczce musi wynosić zero. Suma ładunków formalnych w jonie powinna być równa ładunkowi jonu. Należy pamiętać, że ładunek formalny obliczony dla atomu nie jest rzeczywistym ładunkiem atomu w cząsteczce. Opłata formalna jest jedynie użyteczną procedurą księgową i nie wskazuje na obecność rzeczywistych ładunków.

<h4>Obliczanie ładunku formalnego na podstawie struktur Lewisa</h4>

Wykonuje się następujące kroki, aby przypisać formalne ładunki każdemu atomowi jonu międzyhalogenowego ICl4-.

Krok 1. Podziel pary elektronów wiążących równomiernie dla wszystkich wiązań I – Cl:

<img alt="Figure1" src="https://www.jove.com/files/core/CDNSource/lessons/1065/1065image_1.svg" style="height: 120px;" />

Krok 2. Przypisz samotne pary elektronów do ich atomów. Każdemu atomowi chloru przypisano teraz siedem elektronów, a atomowi jodu osiem.

Krok 3. Odejmij tę liczbę od liczby elektronów walencyjnych dla atomu obojętnego: 
Jod: 7 – 8 = –1 
Chlor: 7 – 7 = 0 
Suma ładunków formalnych wszystkich atomów wynosi –1, co jest identyczne z ładunkiem jonu (–1).

<h4>Wykorzystanie ładunku formalnego do przewidywania struktury molekularnej</h4>

Układ atomów w cząsteczce lub jonie nazywany jest jej strukturą molekularną. W wielu przypadkach wykonanie etapów pisania struktur Lewisa może prowadzić do więcej niż jednej możliwej struktury molekularnej, na przykład wielu różnych wiązań i rozmieszczenia elektronów w postaci wolnych par lub różnych układów atomów. Kilka wskazówek dotyczących ładunku formalnego może być pomocnych w podjęciu decyzji, która z możliwych struktur jest najbardziej prawdopodobna dla konkretnej cząsteczki lub jonu:

<ol style="display: flex; flex-direction: column; gap: 10px;">
	<li>Preferowana jest struktura molekularna, w której wszystkie ładunki formalne wynoszą zero, niż taka, w której niektóre ładunki formalne nie są zerowe.</li>
	<li>Jeśli struktura Lewisa musi mieć niezerowe ładunki formalne, preferowany jest układ z najmniejszymi niezerowymi ładunkami formalnymi.</li>
	<li>Struktury Lewisa są preferowane, gdy sąsiednie ładunki formalne mają wartość zerową lub mają przeciwny znak.</li>
	<li>Wybierając spośród kilku struktur Lewisa o podobnych rozkładach ładunków formalnych, preferowana jest struktura z ujemnymi ładunkami formalnymi na atomach bardziej elektroujemnych.</li>
</ol>

Aby zobaczyć, jak te wytyczne mają zastosowanie, rozważmy kilka możliwych struktur dwutlenku węgla, CO2. Wiadomo, że atom mniej elektroujemny zwykle zajmuje pozycję centralną, ale ładunki formalne są pomocne w zrozumieniu, dlaczego tak się dzieje. Istnieją trzy możliwości struktury: węgiel w środku z dwoma podwójnymi wiązaniami, węgiel w środku z pojedynczym i potrójnym wiązaniem oraz tlen w środku z podwójnymi wiązaniami.

<img alt="Figure2" src="https://www.jove.com/files/core/CDNSource/lessons/1065/1065image_2.svg" style="height: 80px;" />

Porównując trzy ładunki formalne, strukturę po lewej stronie można określić jako preferowaną, ponieważ ma tylko ładunki formalne równe zero.

Innym przykładem jest jon tiocyjanianowy, stworzony z atomu węgla, atomu azotu i atomu siarki, który może mieć trzy różne struktury molekularne: NCS–, CNS– lub CSN–. Ładunki formalne obecne w każdej z tych struktur molekularnych mogą pomóc w wyborze najbardziej prawdopodobnego układu atomów. Możliwe struktury Lewisa i ładunki formalne każdej z trzech możliwych struktur jonu tiocyjanianowego to: węgiel w środku z podwójnymi wiązaniami, azot w środku z podwójnymi wiązaniami i siarka w środku z podwójnymi wiązaniami.

<img alt="Figure3" src="https://www.jove.com/files/core/CDNSource/lessons/1065/1065Image_3.svg" style="height: 95px;" />

Należy zauważyć, że suma ładunków formalnych w każdym przypadku jest równa ładunkowi jonu (–1). Preferowany jest jednak pierwszy układ atomów z węglem w środku, ponieważ ma najmniejszą liczbę atomów o niezerowych ładunkach formalnych. Ponadto umieszcza najmniej elektroujemny atom w środku, a ładunek ujemny na elemencie bardziej elektroujemnym.

W niektórych przypadkach wydaje się, że istnieje więcej niż jedna prawidłowa struktura Lewisa dla cząsteczek i jonów wieloatomowych. Pojęcie opłat formalnych można wykorzystać do ...

Education

JoVE Core

Chemia

Jeden

Chemical Bonding: Basic Concepts

Wiązania chemiczne: Podstawowe pojęcia

KEY TERMS AND CONCEPTS

Kluczowe terminy i pojęcia

lewis structures with formal charge

Lewis structures can sometimes show more than one reasonable arrangement for a molecule or polyatomic ion. Formal charge helps chemists choose the best Lewis structure when that happens. It is a useful way to compare possible structures in chemistry.

Formal charge is the hypothetical charge an atom would have if bonding electrons were shared evenly between the atoms. It can also be found by starting with the valence electrons of the neutral atom, subtracting the nonbonding electrons, and then subtracting the number of bonds on that atom in the Lewis structure. This is a bookkeeping tool, not the actual charge on the atom.

The formal charge of a full structure should also be checked as a whole. For a neutral molecule, the sum of all formal charges must be zero. For an ion, the sum of all formal charges should match the ion’s overall charge.

A common example is the interhalogen ion ICl4−. To assign formal charges, the bonding electron pairs are divided equally among the I–Cl bonds. Then lone pairs are assigned to their atoms. In this structure, each chlorine has seven electrons assigned to it, and iodine has eight. That gives iodine a formal charge of −1 and each chlorine a formal charge of 0, which adds up to the −1 charge of the ion.

Formal charge also helps predict molecular structure when several Lewis structures are possible. A structure with all formal charges equal to zero is preferred over one with nonzero charges. If nonzero charges are needed, the best choice has the smallest charges possible. Structures are also preferred when adjacent formal charges are zero or opposite in sign. When several choices are still possible, the negative charge should be on the more electronegative atom.

Carbon dioxide shows why these rules matter. One possible structure has carbon in the center with two double bonds. Other possibilities place carbon between a single and a triple bond, or place oxygen in the center with double bonds. The structure with carbon in the center and two double bonds is preferred because all of its formal charges are zero.

The thiocyanate ion, NCS−, gives another clear example. It can be written with carbon, nitrogen, or sulfur in the center. The formal charges in each possible Lewis structure help identify the most likely arrangement of atoms. The carbon-centered structure is preferred because it has the fewest atoms with nonzero formal charges. It also places the least electronegative atom in the center and the negative charge on the more electronegative element.

Lewis Structures with Formal Charge

types of chemical bonds

Chemical Bonding and Bond Properties

Chemical bonding explains how atoms and ions join to form molecules and compounds. American chemist Gilbert N. Lewis pioneered chemical bonding theory with the Lewis model. This model helps explain why bonds form, why some are stronger than others, and why compounds have fixed formulas like H2O instead of H4O. Ionic bonding involves ions, which are atoms or molecules with an electrical charge. A cation is a positive ion formed when a neutral atom loses one or more electrons from its valence...

the born-haber cycle

Predicting Ionic Stability with Lattice Energy

Lattice energy helps explain why ionic compounds are stable. It measures the strength of attraction between positive and negative ions in a crystal. In one common definition, lattice energy is the energy required to separate one mole of an ionic solid into gaseous ions, so it has a positive value. Another definition uses the opposite sign and describes the energy released when gaseous ions form a lattice. When checking data, it is important to confirm which convention is being used. In either...

lewis symbols and the octet rule

Valence Electrons, Lewis Symbols, and Bonding

Chemical bonds form when atoms or ions interact in ways that lower the potential energy of a molecule. Gilbert N. Lewis created a simple model to show bond formation using valence electrons, the electrons in the outer shell. In this model, electrons are shared or transferred to help atoms reach a stable electron configuration. The Lewis model helps describe two common bond types. An ionic bond forms when electrons move from a metal to a nonmetal. A covalent bond forms when two nonmetals share...

electronegativity

Electronegativity and Polar Bonds

Electronegativity helps explain why some covalent bonds are nonpolar and others are polar covalent. It is a measure of how strongly an atom attracts shared electrons toward itself. That pull controls how electron density is distributed in a bond. Linus Pauling proposed the first electronegativity values by studying bond energies in heteronuclear molecules such as hydrogen fluoride. He expected the bond energy of HF to be about the average of the bond energies of H2 and F2, or 296 kJ/mol. The...

ionic bonding and electron transfer

Ionic Compounds and Crystal Lattices

Ionic compounds form when positive and negative ions attract each other. A cation is a positive ion, and it forms when an atom loses one or more valence electrons. An anion is a negative ion, and it forms when an atom gains one or more valence electrons. Compounds made of these ions are called ionic compounds, or salts, and the force between them is an ionic bond. The properties of ionic solids help show how strong this attraction is. They usually form rigid, brittle crystals and have high...

trends in lattice energy: ion size and charge

trends-in-lattice-energy-ion-size-and-charge

Lattice Energy Patterns in Ionic Solids

Lattice energy shows how strongly ions hold an ionic solid together. It is the energy required to separate one mole of a solid into its gaseous ions. For sodium chloride, this process requires 769 kJ per mole. The opposite convention may also be used, where lattice energy is the energy released when gaseous ions form the solid. In either case, a larger magnitude means a more stable ionic compound. For ionic crystals, lattice energy follows a pattern based on charge and ion size. The...

covalent bonding and lewis structures

Shared Electrons in Covalent Molecules

Covalent molecules form when atoms share electrons instead of transferring them. This bonding usually happens between nonmetal atoms with similar tendencies to attract electrons. Because the atoms pull on the electrons in a shared way, the bond is held together by mutual attraction. Covalent compounds often have physical properties that differ from ionic compounds. The attraction between neutral molecules is weaker than the attraction between charged ions. As a result, many covalent compounds...

bond polarity, dipole moment, and percent ionic character

bond-polarity-dipole-moment-and-percent-ionic-character

How Bond Polarity Shapes Molecular Dipoles

Bond polarity depends on electronegativity, the ability of an atom to attract shared electrons. The absolute value of the electronegativity difference, or ΔEN, gives a rough guide to bond type. When the difference is very small or zero, the bond is covalent and nonpolar. When it is larger, the bond may be polar covalent or ionic. Examples show how this works in real compounds. H–H has a ΔEN of 0, so it is nonpolar. H–Cl has a ΔEN of 0.9, so it is polar covalent. Na–Cl has a ΔEN of 2.1, so it...

lewis structures of molecular compounds and polyatomic ions

lewis-structures-of-molecular-compounds-and-polyatomic-ions

Drawing Lewis Structures with Valence Electron Counts

Drawing Lewis structures starts with counting valence electrons and building the atom arrangement step by step. Valence electrons are the outer-shell electrons that help show how atoms bond. For ions, a positive charge means one electron is removed for each plus sign, and a negative charge means one electron is added for each minus sign. The next step is to sketch the skeleton structure. The least electronegative atom usually goes in the center, while hydrogen is almost never central. Fluorine...

resonance

Resonance Forms in Lewis Structures

Resonance forms in Lewis structures help explain molecules and ions that cannot be shown correctly with just one drawing. In nitrite ion, NO2−, the Lewis structure can be drawn in two ways. The N-O and N=O bonds switch positions in the two drawings, but the atoms stay in the same arrangement. If nitrite really had one single bond and one double bond, the two bond lengths should be different. A double bond is shorter and stronger than a single bond between the same atoms. Experiments show that...

formal charges

Lewis structures can sometimes show more than one reasonable arrangement for a molecule or polyatomic ion. Formal charge helps chemists choose the best Lewis structure when that happens. It is a useful way to compare possible structures in chemistry. Formal charge is the hypothetical charge an atom would have if bonding electrons were shared evenly between the atoms. It can also be found by starting with the valence electrons of the neutral atom, subtracting the nonbonding electrons, and then...

exceptions to the octet rule

Octet Rule Exceptions in Lewis Structures

Some covalent molecules do not follow the octet rule in their Lewis structures. Their central atoms can fall into three groups: odd-electron molecules, electron-deficient molecules, and hypervalent molecules. These cases show why a Lewis structure may not always give every atom eight valence electrons. Odd-electron molecules have an odd number of valence electrons, so one electron remains unpaired. Molecules with an odd number of electrons are called radicals. Nitric oxide, NO, is one example,...

bond energies and bond lengths

How Bond Energy Predicts Reaction Heat

Bond energy helps explain why molecules stay together and how much heat a reaction may release or absorb. A covalent bond is stronger when more energy is needed to separate the atoms. The energy needed to break one specific covalent bond in one mole of gaseous molecules is called bond energy, or bond dissociation energy. For a diatomic molecule, bond energy is the standard enthalpy change for an endothermic reaction that breaks that bond. The H-H bond is a common example. Its bond energy is...

bonding in metals

Electron Sea Model in Metals

Electron sea model explains how metallic bonding holds metals together. In this model, most metal atoms do not have enough valence electrons to form ionic or covalent bonds in the usual way. Their valence electrons are held loosely because metals have low electronegativity, and their ionization energy is low, so electrons are removed easily. When a metal atom loses these outer electrons, it becomes a positively charged metal ion. The freed electrons form a delocalized electron cloud around...

key terms and concepts

Learn how formal charge helps compare Lewis structures, check total charge, and choose the best arrangement for molecules and ions like CO2 and NCS−.

Lewis Structures with Formal Charge | JoVE K12

chemistry

JoVE Core Chemistry brings general chemistry concepts to life using concise and easy-to-understand animated video lessons. Plus, in the scientist-in-action videos, we demonstrate classical and original research experiments performed in today's laboratories worldwide.

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Physical Science

Study Of Matter

Bonding and compounds

Structure And Properties Of Matter

Chemical bonding

Virginia  Standards of Learning

HIgh School

CH.3

CH.3.d

Physics

PH.9

PH.9.e

new-york-state-science-learning-standards

New York State Science Learning Standards

High School

HS. Structure and Properties of Matter

HS-PS1-3.

HS. Chemical Reactions

HS-PS1-2.

HS-PS1-4.

HS-PS1-12.

Scientific Laws and Theories

Scientific Laws

In science, a law is defined as a concise, verbal or mathematical, statement that summarizes a vast number of experimental observations. ...

The Scientific Method

Chemistry is an empirical science. Scientists often pose questions to understand the chemistry in everyday life and seek answers to these questions. To ...

Classifying Matter by State

Chemistry is the study of matter and the changes it undergoes. Matter is anything that has mass and occupies space. Matter is all around us; the air, ...

Classifying Matter by Composition

Matter: Pure Substances and Mixtures
According to its composition, the matter can be classified into two broad categories &mdash; pure substances and ...

The Atomic Theory of Matter

The earliest recorded discussion of the basic structure of matter comes from ancient Greek philosophers. Leucippus and Democritus argued that all matter ...

Subatomic Particles

Dalton was only partially correct about the particles that make up matter. All matter is composed of atoms, and atoms are composed of three smaller ...

Elements: Chemical Symbols and Isotopes

A chemical symbol is an abbreviation used to indicate an element or an atom of an element. For example, the symbol for mercury is Hg. The same symbol is ...

Use models to explain how the scientific understanding of atomic structure has evolved.

PS.Chm.1.1

Radioactivity and Nuclear Equations

Nuclear chemistry is the study of reactions that involve changes in nuclear structure. The nucleus of an atom is composed of protons and, except for ...

Types of Radioactivity

The most common types of radioactivity are &#945; decay, &#946; decay, &#947; decay, neutron emission, and electron capture.
Alpha (&#945;) decay is the ...

Nuclear Stability

Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10&#8722;15 meters, a nucleus is ...

Nuclear Binding Energy

The difference between the calculated and experimentally measured masses is known as the mass defect of the atom. In the case of helium-4, the mass defect ...

Radioactive Decay and Radiometric Dating

Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. ...

Nuclear Fission

Many heavier elements with smaller binding energies per nucleon can decompose into more stable elements that have intermediate mass numbers and larger ...

Nuclear Power

Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by ...

Nuclear Fusion

The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process ...

Nuclear Transmutation

Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with ...

Use models to compare nuclear reactions including alpha decay, beta decay and gamma decay; nuclear fusion and nuclear fission.

PS.Chm.1.2

Atomic Orbitals

An atomic orbital represents the three-dimensional regions in an atom where an electron has the highest probability to reside. The radial distribution ...

The Pauli Exclusion Principle

The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that ...

The Energies of Atomic Orbitals

In an atom, the negatively charged electrons are attracted to the positively charged nucleus. In a multielectron atom, electron-electron repulsions are ...

The Aufbau Principle and Hund's Rule

To determine the electron configuration for any particular atom, we can build the structures in the order of atomic numbers. Beginning with hydrogen, and ...

electron-configuration-of-multielectron-atoms

Electron Configuration of Multielectron Atoms

The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the ...

Use models to explain how electrons are distributed in atoms.

PS.Chm.1.3

Periodic Classification of the Elements

The periodic table arranges atoms based on increasing atomic number so that elements with the same chemical properties recur periodically. When their ...

The Periodic Table

As early chemists discovered more elements, they realized that various elements could be grouped by their similar chemical behaviors. One such grouping ...

Atomic Mass

Atoms &mdash; and the protons, neutrons, and electrons that compose them &mdash; are extremely small. For example, a carbon atom weighs less than 2 ...

Molar Mass

The identity of a substance is defined not only by the types of atoms or ions it contains but by the quantity of each type of atom or ion. For example, ...

Use the Periodic Table as a model to predict the relative properties of elements based on the pattern of valence electrons in the outermost energy levels of atoms.

PS.Chm.2.1

atomic-radii-and-effective-nuclear-charge

Atomic Radii and Effective Nuclear Charge

The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number ...

Ionic Radii

Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it ...

Ionization Energy

The amount of energy required to remove the most loosely bound electron from a gaseous atom in its ground state is called its first ionization energy ...

Electron Affinity

The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion).



This process can be either ...

Construct an explanation to infer the atomic size, reactivity, electronegativity, and ionization energy of an element based on its position in the Periodic Table.

PS.Chm.2.2

Types of Chemical Bonds

Chemical bonding theories were pioneered by American chemist Gilbert&#xA0;N. Lewis. He developed a model called the Lewis model to explain the type and ...

Lewis Symbols and the Octet Rule

Chemical bonds are complex interactions between two or more atoms or ions, which reduce the potential energy of the molecule. Gilbert N. Lewis developed a ...

Ionic Bonding and Electron Transfer

Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence ...

The Born-Haber Cycle

Lattice Energy&#xA0;

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a ...

Trends in Lattice Energy: Ion Size and Charge

An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure ...

Covalent Bonding and Lewis Structures

Compared to ionic bonds, which results from the transfer of electrons between metallic and nonmetallic atoms, covalent bonds result from the mutual ...

Electronegativity

Whether a bond is nonpolar or polar covalent is determined by a property of the bonding atoms called electronegativity.&#xA0;

Electronegativity values of ...

Bond Polarity, Dipole Moment, and Percent Ionic Character

Bond Polarity

The absolute value of the difference in electronegativity (&Delta;EN) of two bonded atoms provides a rough measure of the polarity to be ...

Lewis Structures of Molecular Compounds and Polyatomic Ions

To draw Lewis structures for complicated molecules and molecular ions, it is helpful to follow a step-by-step procedure as outlined:


	Determine the ...

Resonance

The Lewis structure of a nitrite anion (NO2&minus;) may actually be drawn in two different ways, distinguished by the locations of the N-O and N=O ...

In some cases, there are seemingly more than one valid Lewis structures for molecules and polyatomic ions. The concept of formal charges can be used to ...

Exceptions to the Octet Rule

Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:


	...

Bond Energies and Bond Lengths

Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, ...

Analyze and interpret data to explain the mechanisms and properties of the two main types of intramolecular (ionic and covalent) bonds.

molecular-comparison-of-gases-liquids-and-solids

Molecular Comparison of Gases, Liquids, and Solids

Particles in a solid are tightly packed together (fixed shape) and often arranged in a regular pattern; in a liquid, they are close together with no ...

Intermolecular vs Intramolecular Forces

Intermolecular forces (IMF) are electrostatic attractions arising from charge-charge interactions between molecules. The strength of the intermolecular ...

Intermolecular Forces

Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions ...

comparing-intermolecular-forces-melting-point-boiling-point

Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility

Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, ...

Construct an explanation to summarize the influences intermolecular forces have on the properties of chemical compounds.

PS.Chm.3.2

Analyze the structure of atoms and isotopes.

Lewis Structures with Formal Charge

Description

Transcript

Tags

More videos by Standards