Name: atomic elements, molecules, and bonds
Uploaded: 2020-09-03T13:38:25.000Z
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K12 Standards

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North Carolina K-12 Science Standard Course of Study

9-12

Chemistry

Matter and its Interactions

PS.Chm.3.3

Molecules and Compounds

Dans la nature, toute la matière est composée d'unités chimiques de base appelées éléments ayant des propriétés physiques et chimiques spécifiques. Le tableau périodique énumère un total de 118 éléments identifiés à ce jour. L'unité constitutive de chaque élément est l'atome.Certains éléments comme l'hélium, le néon, l'argent ou le platinum existent en tant qu'unités d'atomes individuels indépendants. D'autres éléments comme l'hydrogène, l'oxygène ou le soufre existent en tant qu'unités de deux ou plus atomes identiques. Ces atomes multiples sont maintenus ensemble par de fortes forces électrostatiques appelées liaisons chimiques, formant des unités stables appelées molécules.En outre, deux ou plusieurs éléments différents peuvent également se combiner pour former des molécules comme l'eau ou le fructose. Telles molécules qui sont formées par la combinaison d'atomes de deux éléments ou plus, chimiquement unis dans une proportion fixe, sont également appelées composants. Par conséquent, les molécules d'eau et de fructose sont également des composants.L'eau est une molécule formée de deux atomes d'hydrogène et d'un atome d'oxygène. En revanche, le fructose est une molécule qui contient six atomes de carbone, douze atomes d'hydrogène, et six atomes d'oxygène. Les atomes individuels dans un composant sont maintenus ensemble par des liaisons chimiques, dictant le type de composant formé tel qu'un composant ionique ou moleculaire.Les composants moléculaires covalenteur, comme l'eau, se forment lorsque les atomes non métalliques se réunissent et partagent leurs électrons de valence via une liaison covalente. Les électrons partagés entre deux atomes réduisent l'énergie potentielle et créent des molécules plus stables par rapport aux atomes individuels. Les composés ioniques, comme le chlorure de sodium, se forment lorsque les atomes métalliques et non métalliques se rejoignent.Les métaux perdent facilement des électrons devenant des cations, tandis que les non-métaux gagnent facilement des électrons devenant des anions. Ainsi, les atomes métalliques transfèrent des électrons à des atomes non métalliques et les interactions électrostatiques entre les ions chargés de manière opposée forment des liaisons ioniques. La capacité des éléments à former des composants contribue à la grande diversité de la matière qui existe dans la nature.

molécules et composés

<h4>Atomes et molécules </h4>
 
 Tout dans l'univers est constitué de matière, et la matière est composée d'une combinaison d'éléments. Un atome est la plus petite unité d'un élément qui conserve toutes les propriétés de l'élément. Par exemple, une pièce en argent est constituée d'atomes d'argent, et chaque atome d'argent conserve les propriétés uniques de l'élément — l'argent.  
 
 Les éléments sont des substances pures constituées d'atomes identiques qui ne peuvent pas être décomposés en substances plus simples par des transformations chimiques. Les éléments atomiques contiennent des atomes seuls comme unité de base. Le carbone est composé d'atomes de carbone et le sodium est composé d'atomes de sodium. La plupart des éléments sont des éléments atomiques. Il y a, cependant, quelques éléments qui existent en tant que combinaison d'atomes et qui ne sont jamais trouvés dans la nature en tant qu'atomes simples. Ces éléments sont appelés des éléments moléculaires. Les éléments moléculaires existent sous la forme de molécules avec deux atomes ou plus liés ensemble. Ils peuvent être diatomiques, comme les gaz hydrogène (H2), oxygène (O2) ou chlore (Cl2), ou polyatomiques comme le soufre (S8) et le phosphore (P4).  
 
 Une molécule est constituée de deux atomes ou plus, qui sont reliés par des forces intenses appelées des liaisons chimiques. Une molécule peut être constituée de deux ou plusieurs atomes identiques, ou de deux ou plusieurs atomes différents. Lorsque la molécule est constituée d'atomes de deux ou plusieurs éléments différents qui sont combinés suivant des rapports de nombres entiers fixes, la molécule est également un composé. Par exemple, l'eau est un composé, et chaque molécule d'eau (H2O) est une unité qui contient deux atomes d'hydrogène et un atome d'oxygène. La molécule glucose (C6H12O6) est aussi un composé qui contient six atomes de carbone, douze atomes d'hydrogène et six atomes d'oxygène. 
 
 Les composés sont des substances pures composées de deux éléments ou plus dans des proportions fixes et définies. Les composés sont classés comme moléculaires ou ioniques en fonction des liaisons présentes. 
 
 <h4>Composés </h4>
 
 La nature des forces d'attraction qui maintiennent les atomes ensemble à l'intérieur d'un composé détermine le type de liaison chimique formée. Le transfert complet d'électrons entre un atome métallique et un atome non métallique entraîne la formation d'ions avec des charges de signes opposés. L'attraction électrostatique entre les ions est appelée liaison ionique, et les composés formés par des liaisons ioniques sont des composés ioniques. Par exemple, le chlorure de sodium NaCl est un composé ionique. 
 
 La mise en commun d'électrons entre deux atomes non métalliques ou plus donne des liaisons covalentes, et les composés formés par des liaisons covalentes sont appelés composés covalents ou composés moléculaires. Les liaisons covalentes sont les forces d'attraction entre les noyaux chargés positivement des atomes liés et les électrons chargés négativement partagés entre les atomes. 
 
 Ce texte est adapté de <a href="https://openstax.org/books/chemistry-2e/pages/2-6-molecular-and-ionic-compounds">OpenStax Chemistry 2e, Section 2.6 : Composés moléculaires et ioniques.</a>

Molécules et composés

Atomes et molécules

Tout dans l’univers est composé de matière, et la matière est composée d’une combinaison d’éléments. Un atome est la plus petite unité de ...

Education

Enseignement

JoVE Core

Chimie

Molecules, Compounds, and Chemical Equations

Molécules, composés et équations chimiques

molecules-compounds-and-chemical-equations

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

atomic elements, molecules, and bonds

Matter is made of elements, and elements are built from atoms. An atom is the smallest unit of an element that still keeps that element’s properties. A silver coin, for example, is made of silver atoms. Each atom keeps the unique properties of silver.

Elements are pure substances made of identical atoms. They cannot be broken down into simpler substances by chemical changes. Most elements are atomic elements, which use single atoms as their basic unit. Carbon and sodium are examples of atomic elements.

Some elements do not occur as single atoms in nature. These are called molecular elements. They exist as molecules made of two or more bonded atoms. Some are diatomic, such as hydrogen (H2), oxygen (O2), and chlorine (Cl2). Others are polyatomic, such as sulfur (S8) and phosphorous (P4).

A molecule is a group of two or more atoms joined by strong chemical bonds. The atoms in a molecule may be the same, or they may be different. When a molecule contains atoms from two or more different elements in fixed whole number ratios, it is also a compound. Water is a compound, and each H2O molecule has two hydrogen atoms and one oxygen atom. Glucose (C6H12O6) is another compound, with six carbon atoms, twelve hydrogen atoms, and six oxygen atoms.

Compounds are pure substances made of two or more elements in fixed, definite proportions. They are classified as molecular or ionic based on the bonds they contain. The kind of attraction between atoms determines the bond type. When electrons transfer completely from a metal atom to a nonmetal atom, oppositely charged ions form. The electrostatic attraction between those ions is an ionic bond, and the result is an ionic compound such as sodium chloride (NaCl). When two or more nonmetal atoms share electrons, they form covalent bonds. Compounds formed this way are covalent, or molecular, compounds.

Atomic Elements, Molecules, and Bonds

molecules and compounds

Matter is made of elements, and elements are built from atoms. An atom is the smallest unit of an element that still keeps that element’s properties. A silver coin, for example, is made of silver atoms. Each atom keeps the unique properties of silver. Elements are pure substances made of identical atoms. They cannot be broken down into simpler substances by chemical changes. Most elements are atomic elements, which use single atoms as their basic unit. Carbon and sodium are examples of atomic...

molecular models

Molecular Model Types in Chemistry

Molecular models help chemists and students visualize the structures and shapes of atoms and molecules. They represent the molecular architecture of chemical compounds in a way that is easier to study than formulas alone. Skeletal models are simple two-dimensional drawings of compounds. They show the molecular framework, or the bonds, without drawing every atom. In this model, many carbon and hydrogen atoms are not shown directly. Their positions are implied by the ends and junctions of the...

organic compounds

Organic Molecules in Everyday Chemistry

Organic molecules are carbon-based compounds found in living things and in many everyday products. Most organic compounds have carbon as the main element, bonded to hydrogen and other carbon atoms. Some carbon-containing substances, such as carbonates, cyanides, and simple oxides like CO and CO2, are not classified as organic. Carbon can form up to four strong bonds, which helps explain why organic compounds can make chains and rings of many sizes and shapes. These molecules appear in...

formula mass and mole concepts of compounds

formula-mass-and-mole-concepts-of-compounds

Chemical Formula Mass and Percent Composition

Chemical formula mass and percent composition help describe the makeup of compounds. A chemical formula shows which atoms are present and how many of each atom appear in a substance. For covalent compounds, the formula shows the atoms in one molecule. That is why formula mass can also be called molecular mass. Chloroform, CHCl3, is one example. Its formula shows one carbon atom, one hydrogen atom, and three chlorine atoms. The molecular mass is the sum of their average atomic masses. Ionic...

experimental determination of chemical formula

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Finding Empirical and Molecular Formulas

Chemical formulas show the elemental makeup of a compound. When a formula is unknown, scientists often start by measuring the masses of the elements in the sample. Those mass data are then used to find the simplest whole-number ratio of atoms, which gives the empirical formula. To get from mass to atom ratio, the masses of the elements are first converted to moles using molar masses. Chemical formulas describe numbers of atoms, not masses, so this step is necessary. In one example, 1.71 grams...

chemical equations

Reading Chemical Equations and Balancing Them

Chemical equations show the identities and relative amounts of substances in a chemical reaction. The substances that react are called reactants, and their formulas are written on the left side of the equation. The substances formed are called products, and their formulas are written on the right side. A plus sign (+) separates formulas on the same side, and an arrow (→) shows the change from reactants to products. The numbers in a chemical equation are shown with coefficients. A coefficient...

key terms and concepts

Learn how atoms form elements, molecules, and compounds, and compare ionic and covalent bonds using examples like water, glucose, and sodium chloride.

Atomic Elements, Molecules, and Bonds | JoVE K12

chemistry

JoVE Core Chimie anime les concepts de chimie générale en utilisant des leçons vidéo concises et faciles à comprendre. De plus, nos vidéos de scientifiques à l'action présentent des expériences de recherche, classiques ou insolites, effectuées dans des laboratoires modernes du monde entier.

PS.Chm.4.3

Physical Science

PS.PSc.1.1

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Ohio’s Learning Standards and Model Curriculum

Study Of Matter

Classification of matter

Virginia  Standards of Learning

HIgh School

CH.3

CH.3.a

Alabama Course of Study Science

Matter and Its Interactions

9-12.PS.3.4.c

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C-PS1-3.

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Scientific Laws and Theories

Scientific Laws

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The Scientific Method

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Matter: Pure Substances and Mixtures
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The Atomic Theory of Matter

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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

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

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Radioactivity and Nuclear Equations

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Types of Radioactivity

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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

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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

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PS.Chm.1.3

Periodic Classification of the Elements

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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

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PS.Chm.2.1

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Atomic Radii and Effective Nuclear Charge

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Ionic Radii

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Ionization Energy

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Electron Affinity

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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

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Ionic Bonding and Electron Transfer

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The Born-Haber Cycle

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Covalent Bonding and Lewis Structures

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Lewis Structures of Molecular Compounds and Polyatomic Ions

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Resonance

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Formal Charges

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Exceptions to the Octet Rule

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	...

Bond Energies and Bond Lengths

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PS.Chm.3.1

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Molecular Comparison of Gases, Liquids, and Solids

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Intermolecular vs Intramolecular Forces

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Intermolecular Forces

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

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surface-tension-capillary-action-and-viscosity

Surface Tension, Capillary Action, and Viscosity

Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded ...

Hydrogen Bonds

Hydrogen BondsHydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, ...

Van der Waals Interactions

Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions ...

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

PS.Chm.3.2

Atoms and Molecules

Everything in the universe is made up of matter, and matter is composed of a combination of elements. An atom is the smallest unit of ...

Chemical Formulas

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Molecular Models

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Classification of Elements and Compounds

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Ionic Compounds: Formulas and Nomenclature

An element composed of atoms that readily lose electrons (a metal) can react with an element composed of atoms that readily gain electrons (a nonmetal) to ...

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Molecular Compounds: Formulas and Nomenclature

Molecular compounds or covalent compounds result when atoms share electrons to form covalent bonds. Since there is no electron transfer, molecular ...

Use models to predict chemical names and formulas including ionic (binary & ternary), acidic, and binary covalent compounds.

Analyze the structure of atoms and isotopes.

Atomic Elements, Molecules, and Bonds

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