Name: predicting ion charges on the periodic table
Uploaded: 2020-09-03T13:38:25.000Z
Duration: 3 min 27 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

Physical Science

Matter and its Interactions

PS.PSc.1.5

Ions and Ionic Charges

原子是质子和电子数相等的 中性粒子。元素是由质子的数量来定义的，而质子的数量 是不变的；然而，许多原子 可以获得或失去一个或多个电子 而成为带电粒子。当一个原子或分子获得或失去电子时，它就被称为离子。电子的质量比质子小得多，因此对原子质量的贡献并不大。因此，一个离子的原子质量 与其中性原子的原子质量基本相同。当原子或分子失去电子时，它们被称为阳离子。阳离子带正电荷是因为它们 有更多带正电荷的质子，而不是带负电荷的电子。阳离子被赋予与其元素相同的名称，后跟"离子"一词。一个钙原子有 20 个质子和 20 个电子。它失去两个电子，就会变成一个含有 20 个质子 和 18 个电子的钙离子。因为现在它的正电荷 比负电荷多了两个，所以它的总电荷是正二。离子的化学符号在书写时 先写为原子的化学符号，再将电荷写在右上标的位置。因此，钙离子的化学符号 被写成 C-a-2 当原子或分子获得电子时，它们被称为阴离子。阴离子带负电荷，因为它们的 电子比质子多。阴离子通过在元素名称中添加后缀 ide 来 命名。一个氟原子有 9 个质子和 9 个电子。氟原子获得一个电子，就会变成一个含有 9 个 质子和 10 个电子的氟离子。因为现在它的负电荷 比正电荷多了一个，所以它的总电荷是负一。氟离子的化学符号写为 F 对于带一个正电荷或负电荷的离子，通常省略这个一。原子在形成离子时会失去或获得 特定数量的电子。对于主族元素形成的离子的许多电荷 可以用周期表来预测。位于元素周期表左侧的金属，会失去电子。第一主族的碱金属都会失去一个电子，当它们变成离子时都带一个正电荷。第二主族的碱土金属会失去两个电子 并带有两个正电荷。位于元素周期表右侧的非金属元素，会获得电子。第 17 组的卤素会获得一个电子，并带有一个负电荷。第 16 组的元素会获得两个电子，并带有两个负电荷。许多过渡金属可以形成带不同电荷的阳离子。第 18 组的惰性气体一般不形成离子。

<ol>
	<li>詹森，威廉 B. "离子电荷的正确书写。"化学教育杂志 89，第 8 期（2012 年）:1084-1085。</li>
	<li>施密德，罗兰。"惰性气体构型——不是驱动力，而是化学游戏规则。"化学教育杂志 80，第 8 期（2003）:931。</li>
	<li>Gillespie， Ronald J. "电子密度、原子电荷以及离子、共价键和极性键。化学教育杂志 78，第 12 期（2001）:1688. 
	 </li>
</ol>

离子和离子电荷

在通常的化学反应中，原子核-包含每个原子的质子和中子，从而标识元素＆mdash;保持不变。但是，电子可以通过从其他原子转移而添加到原子上，也可以通过转移到其他原子而丢失，或者与其他原子共享。电子在原子之间的转移和共享决定着元素的化学性质。在某些化合物的形成过程中，原子获得或失去电子，形成称为离子的带电粒子。
 
 当原子失去电子时，它会形成称为阳离子的正离子。阳离子比电子具有更多的质子。同样，当原子获得电子时，它会形成称为阴离子的负离子。阴离子比质子具有更多的电子。
 
 元素周期表有助于预测原子是形成阴离子还是阳离子，以及生成的离子的电荷。从周期表的最左到右移动，主族金属的原子失去足够的电子，从而使它们剩下的电子数量与之前的稀有气体的原子数量相同。它们形成电荷等于基团号的阳离子。为了说明这一点，碱金属原子（第1组）失去一个电子，并形成带有1+电荷的阳离子；碱土金属（第2组）会失去两个电子，并形成带有2+电荷的阳离子，依此类推。例如，具有20个质子和20个电子的中性钙原子很容易失去两个电子。这产生具有20个质子，18个电子和2+电荷的阳离子。它具有与先前的稀有气体氩原子相同的电子数量，并表示为Ca2+。金属离子的名称与形成金属离子的名称相同，因此Ca2+ 称为钙离子。
 
 非金属元素的原子通常从周期表的最右边移动到左侧，获得足够的电子，以使它们具有与周期表中下一个稀有气体原子相同数量的电子。它们形成带负电荷的阴离子，该负电荷等于从稀有气体中移出的基团数。例如，第17族元素的原子（稀有气体剩下的一组）的原子获得一个电子，并形成具有-1和-的负离子。电荷; 第16组元素（剩下的两个组）的原子获得两个电子，并形成2负的离子。充电等等。例如，具有35个质子和35个电子的中性溴原子可以获取一个电子，从而为其提供36个电子。这将产生一个具有35个质子，36个电子和1负的阴离子。收费。它具有与下一个稀有气体原子相同的电子数量，并表示为Br−。
 
 在许多情况下，可以将离子电荷与周期表中基团位置之间的趋势用作指导。但是，当其朝着元素周期表的中心移动时，其预测值会降低。过渡金属和其他一些金属通常会显示出可变电荷，这些电荷无法通过表中的位置预测。例如，铜可以形成带1+或2+电荷的离子，铁可以形成带2+或3+电荷的离子。
 
 本文改编自<a href="https://openstax.org/books/chemistry-2e/pages/2-6-molecular-and-ionic-compounds"> Openstax，化学2e，第2.6节：分子和离子化合物</a>。

在普通的化学反应中，原子核——包含每个原子的质子和中子，从而确定元素的种类——保持不变……

Education

教育

JoVE Core

Chemistry

化学

Atoms and Elements

原子与元素

KEY TERMS AND CONCEPTS

关键术语与概念

predicting ion charges on the periodic table

Ion charges can often be predicted from an element’s position on the periodic table. In chemical reactions, the nucleus stays unchanged, but electrons may be transferred, lost, or shared. When atoms gain or lose electrons during compound formation, they become ions, which are electrically charged particles.

A positive ion is called a cation. A cation has more protons than electrons because it lost electrons. A negative ion is called an anion. An anion has more electrons than protons because it gained electrons.

The periodic table gives useful clues about ion charge. Main-group metals on the far left usually lose electrons until they have the same number of electrons as the preceding noble gas. Their cation charge often matches the group number. For example, a Group 1 alkali metal forms a 1+ cation, and a Group 2 alkaline earth metal forms a 2+ cation.

Calcium shows this pattern clearly. A neutral calcium atom has 20 protons and 20 electrons. It can lose two electrons to form Ca2+, which has 20 protons, 18 electrons, and a 2+ charge. This ion has the same number of electrons as argon. The name of the metal ion is the same as the metal atom, so Ca2+ is called a calcium ion.

Nonmetals on the far right usually gain electrons to reach the electron count of the next noble gas. Their anion charge often matches how many groups they are away from the noble gases. Group 17 elements usually gain one electron to form 1− anions, and Group 16 elements usually gain two electrons to form 2− anions.

Bromine is one example. A neutral bromine atom has 35 protons and 35 electrons. It can gain one electron to form Br− with 35 protons, 36 electrons, and a 1− charge. This ion has the same number of electrons as krypton. The trend between group position and ion charge helps in many cases, but it becomes less reliable near the center of the periodic table. Transition metals and some other metals often have variable charges. Copper can form 1+ or 2+ ions, and iron can form 2+ or 3+ ions.

Predicting Ion Charges on the Periodic Table

predicting-ion-charges-on-the-periodic-table

the atomic theory of matter

Dalton’s Laws and Early Atomic Ideas

Dalton’s atomic theory explains matter with atoms, elements, and compounds. It also shows how chemical changes follow simple laws. This idea gave chemistry a microscopic model for what can be seen in the lab. The earliest recorded ideas about matter came from ancient Greek philosophers. Leucippus and Democritus said all matter was made of tiny, finite particles called atomos, meaning “indivisible.” Aristotle and others later argued that matter was made from four elements: fire, earth, air, and...

subatomic particles

Atomic Structure: Protons, Neutrons, and Electrons

Atomic structure is built from three subatomic particles: protons, neutrons, and electrons. Atoms make up all matter, and these particles explain an atom’s mass and charge. The electron was first identified at the end of the 19th century by J.J. Thomson. He used a cathode ray tube, a sealed glass tube with almost all the air removed and two metal electrodes. When high voltage was applied, a visible beam called a cathode ray formed. The beam bent toward positive charge and away from negative...

elements: chemical symbols and isotopes

Reading Element Symbols and Isotope Notation

Chemical symbols and isotope notation help identify elements and their atoms. A chemical symbol is an abbreviation for an element or a single atom of that element. Mercury, for example, is written as Hg. The same symbol can point to one atom in the microscopic domain or to many atoms of the element in a container or sample. Many symbols come from the element’s common English name. Others come from Latin, Greek, or German names. Aluminum uses Al, while iron uses Fe from the Latin word Ferrum.

ions and ionic charges

Ion charges can often be predicted from an element’s position on the periodic table. In chemical reactions, the nucleus stays unchanged, but electrons may be transferred, lost, or shared. When atoms gain or lose electrons during compound formation, they become ions, which are electrically charged particles. A positive ion is called a cation. A cation has more protons than electrons because it lost electrons. A negative ion is called an anion. An anion has more electrons than protons because it...

the periodic table

Periodic Table Patterns and Element Groups

The periodic table organizes elements by repeating patterns in their properties. Chemists first noticed that some elements behaved alike, so they grouped them by chemical behavior. Lithium, sodium, and potassium are one example. They are shiny and conduct heat and electricity well. Calcium, strontium, and barium form another group with similar physical and chemical properties. Yet these two groups are not the same. The lithium group is much more reactive, and its elements form oxygen compounds...

atomic mass

Average Atomic Mass and Isotopes

Average atomic mass explains why many elements on the periodic table have decimal values. Atoms are extremely small, so scientists use the atomic mass unit, or amu, to measure them. A carbon atom weighs less than 2 × 10−23 g, and the amu is defined from carbon-12. One amu is exactly 1/12 the mass of one carbon-12 atom, which is 1.6605 × 10−24 g. The dalton (Da) and the unified atomic mass unit (u) mean the same thing as the amu. For a single atom, atomic mass is usually close to its mass...

molar mass

Mole, Mass, and Avogadro’s Number

The mole links mass and the number of particles in a substance. It gives chemists a standard way to count atoms and molecules in samples that are far too small to see. It also helps show why substances with the same kinds of atoms can still have very different properties, like water, H2O, and hydrogen peroxide, H2O2. The mole is an amount unit, like a pair or a dozen. One mole contains 6.02214076 × 10^23 discrete entities, such as atoms or molecules. This number is usually rounded to 6.022 ×...

key terms and concepts

Learn how the periodic table helps predict cation and anion charges, with examples like calcium, bromine, copper, and iron for grades 9–12.

Predicting Ion Charges on the Periodic Table | JoVE K12

chemistry

JoVE Core 化学通过简单明了且通俗易懂的动画视频课程，将普通化学概念带入到现实生活当中。此外，在科学家行动视频中，我们演示了在实验室中进行的经典和原始研究实验。

Louisiana Student Standards for Science

High School

Matter And Its Interactions

HS-PS1-1

motion-and-stability-forces-and-interactions

Motion And Stability: Forces And Interactions

HS-PS2-6

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Study Of Matter

Atoms

Tennessee Academic Standards

Matter and Its Interactions

CHEM1.PS1.13

Virginia  Standards of Learning

HIgh School

CH.2

CH.2.a

PS.4

PS.4.a

Arizona Science Standards

HS+C.P1

HS+C.P1U1.1

HS.P1

HS.P1U1.2

Alabama Course of Study Science

9-12.C.1.1.a

9-12.C.1.1.b

9-12.PS.3.4

9-12.PS.3.4.d

Florida Department of Education

SC.912.P.8

SC.912.P.8.4

Texas Essential Knowledge and Skills

Chemistry and Physics

IPC.7

IPC.7.A

Georgia Standards of Excellence

SPS1.

Properties of Atoms, Ions, and Isotopes

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 ...

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 ...

Molecules and Compounds

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 ...

Solution Formation

There is no one solvent that can dissolve every type of solute. Some substances that readily dissolve in a certain solvent might be insoluble in a ...

Colloids

Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera ...

Construct an explanation to classify matter as a pure substance or mixture; homogeneous or heterogeneous; element or compound; solution, colloid or suspension.

PS.PSc.1.1

Phase Transitions

Whether solid, liquid, or gas, a substance&#39;s state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the ...

phase-transitions-vaporization-and-condensation

Phase Transitions: Vaporization and Condensation

The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize ...

Vapor Pressure

When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules move randomly about, they will occasionally ...

Clausius-Clapeyron Equation

The equilibrium between a liquid and its vapor depends on the temperature of the system; a rise in temperature causes a corresponding rise in the vapor ...

Phase Transitions: Melting and Freezing

Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy ...

phase-transitions-sublimation-and-deposition

Phase Transitions: Sublimation and Deposition

Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and ...

Heating and Cooling Curves

When a substance&#8212;isolated from its environment&#8212;is subjected to heat changes, corresponding changes in temperature and phase of the substance ...

Phase Diagrams

A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. ...

Use models to compare the phases of matter and the physical changes they undergo.

PS.PSc.1.2

physical-and-chemical-properties-of-matter

Physical and Chemical Properties of Matter

The characteristics that enable us to distinguish one substance from another are called properties.

Physical Properties of Matter

A physical property is ...

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, ...

Carry out investigations to compare physical and chemical properties of matter.

PS.PSc.1.3

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 ...

The Bohr Model

Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded ...

Emission Spectra

When solids, liquids, or condensed gases are heated sufficiently, they radiate some of the excess energy as light. Photons produced in this manner have a ...

The de Broglie Wavelength

In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a ...

The Uncertainty Principle

Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that ...

Use models to interpret the data presented in Bohr diagrams and electron dot diagrams for neutral atoms of elements 1 through 18.

PS.PSc.1.4

In ordinary chemical reactions, the nucleus &mdash; which contains the protons and neutrons of each atom and thus identifies the element &mdash; remains ...

Use models to compare representations of atoms, ions, and isotopes.

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 ...

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 ...

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 ...

Alkali Metals

Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the ...

Halogens

Group 17 elements, known as halogens, are nonmetals. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine a solid. ...

Noble Gases


The elements in group 18 are noble gases (helium, neon, argon, krypton, xenon, and radon). They earned the name &ldquo;noble&rdquo; because they were ...

Use the Periodic Table as a model to predict the relative properties (metallic/nonmetallic character, ionic charge, and reactivity) and arrangement of elements based on the pattern of valence electrons in the outermost energy levels of atoms.

PS.PSc.1.6

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 ...

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 ...

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 ...

Bonding in Metals

Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Dr&#xFC;de called the ...

Construct an explanation to classify the type of chemical bond that occurs (covalent, ionic, or metallic) in a given substance.

PS.PSc.2.1

Nomenclature of Alkanes

In the late 19th-century, the number of new chemical compounds discovered increased tremendously. Hence, the necessity arose to develop a naming system ...

Nomenclature of Alkenes

The IUPAC naming system for alkenes replaces -an- with -en- in the corresponding parent alkanes. Accordingly, a simple alkene replaces the -ane suffix of ...

Nomenclature of Alkynes

Alkynes are unsaturated hydrocarbons characterized by the presence of carbon-carbon triple bonds and have a general formula CnH2n-2. The nomenclature of ...

structure-and-nomenclature-of-alcohols-and-phenols

Structure and Nomenclature of Alcohols and Phenols

Overview 
Alcohols are one of the most important functional groups in organic chemistry. The name of alcohol comes from the hydrocarbon from which it is ...

Structure and Nomenclature of Ethers

Structure and Bonding
Ethers are organic compounds with an ether functional group which is characterized by an oxygen atom connected to two &#8212; ...

IUPAC Nomenclature of Aldehydes

Aldehydes are named based on the systematic nomenclature rules set by the IUPAC. For acyclic aldehydes, the longest carbon chain containing the aldehydic ...

IUPAC Nomenclature of Ketones

Like aldehydes, ketones are named using IUPAC rules; in this case, by replacing &#8220;e&#8221; in the name of the longest hydrocarbon chain with ...

Use models to apply International Union of Pure and Applied Chemistry (IUPAC) conventions to name and write formulas for simple compounds.

PS.PSc.2.2

Understand types, properties, and structure of matter.

Predicting Ion Charges on the Periodic Table

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