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

Os átomos são partículas neutras com igual número de prótons e elétrons. Um elemento é definido pelo número de prótons, que não mudam;no entanto, muitos átomos podem ganhar ou perder um ou mais elétrons para se tornarem uma partícula carregada. Quando um átomo ou uma molécula ganha ou perde elétrons é chamado de íon.é chamado de íon. Os elétrons, que são muito mais pequenos em massa do que os prótons, não contribuem significativamente para a massa atômica. Portanto, a massa atômica de um íon é essencialmente a mesma que a massa atômica de um átomo neutro.Quando os átomos ou as moléculas perdem elétrons são chamados de cátions. Os cátions têm carga positiva porque têm mais prótons, que têm carga positiva, do que elétrons, que têm carga negativa Os cátions recebem o mesmo nome que o seu elemento, seguido da palavra íon. Um átomo de cálcio tem 20 prótons e 20 elétrons.Perde dois elétrons para se tornar um íon de cálcio com 20 prótons e 18 elétrons. Como agora tem mais duas cargas positivas do que negativas, tem uma carga global de dois positivo. O símbolo químico de um íon é escrito como o símbolo químico do átomo com a carga indicada à direita.O símbolo químico para um íon de cálcio é, portanto, escrito como C-A-mais dois. Quando os átomos ou as moléculas ganham elétrons são chamados de aníons. Os aníons têm carga negativa porque têm mais elétrons do que prótons.Os aníons surgem adicionando o sufixo eto ao nome do seu elemento. Um átomo de flúor tem 9 protões e 9 elétrons. O flúor ganha um elétron para se tornar um íon de fluoreto com 9 prótons e 10 elétrons.Porque agora tem mais uma carga negativa do que positiva, tem uma carga global negativa. O símbolo químico do flúor é escrito como F menos. Normalmente o um é omitido para os íons com uma carga positiva ou negativa.Os átomos perderão ou ganharão números específicos de elétrons ao formarem um íon. Muitas das cargas para os íons formados pelos elementos principais do grupo podem ser previstas utilizando a tabela periódica. Os metais, no lado esquerdo da tabela periódica, perderão elétrons.Os metais alcalinos do grupo 1 perdem todos um elétron e têm uma carga positiva quando se tornam um íon. Os metais alcalinos de terra do grupo 2 perdem dois elétrons e têm uma carga positiva de dois. Os não metálicos, do lado direito da tabela periódica, ganharão elétrons.Os halogêneos do grupo 17 ganham um elétron e têm uma carga negativa de um. Os elementos do grupo 16 ganham dois elétrons e terão uma carga negativa de dois. Muitos metais de transição podem formar cátions com cargas diferentes.Os gases nobres do grupo 18, geralmente, não formam íons.

<ol>
	<li>Jensen, William B. "A escrita adequada de cargas iônicas." Jornal de Educação Química 89, nº 8 (2012): 1084-1085.</li>
	<li>Schmid, Roland. "A configuração do gás nobre - não a força motriz, mas a regra do jogo em química." Jornal de educação química 80, nº 8 (2003): 931.</li>
	<li>Gillespie, Ronald J. "Densidades eletrônicas, cargas atômicas e ligações iônicas, covalentes e polares." Journal of Chemical Education 78, nº 12 (2001): 1688. 
	 </li>
</ol>

iões e cargas iónicas

Nas reações químicas comuns, o núcleo — que contém os protões e neutrões de cada átomo e, assim, identifica o elemento — permanece inalterado. Os eletrões, no entanto, podem ser adicionados aos átomos através da transferência de outros átomos, perdidos por transferência para outros átomos, ou partilhados com outros átomos. A transferência e partilha de eletrões entre átomos governam a química dos elementos. Durante a formação de alguns compostos, os átomos ganham ou perdem eletrões para formar partículas carregadas eletricamente chamadas iões.

Quando um átomo perde eletrões, forma um ião positivo chamado catião. Os catiões têm mais protões do que os eletrões. Da mesma forma, quando um átomo ganha eletrões, forma um ião negativo chamado anião. Os aniões têm mais eletrões do que protões.

A tabela periódica ajuda a prever se um átomo irá formar uma anião ou um catião, e também a carga do ião resultante. Indo do lado esquerdo para o direito na tabela periódica, átomos de metais representativos perdem eletrões suficientes para deixá-los com o mesmo número de eletrões que um átomo do gás nobre anterior. Eles formam catiões com uma carga igual ao número do grupo. Para ilustrar, um átomo de um metal alcalino (Grupo 1) perde um eletrão e forma um catião com carga 1+; um metal alcalinoterroso (Grupo 2) perde dois eletrões e forma um catião com carga 2+, e assim por diante. Por exemplo, um átomo de cálcio neutro, com 20 protões e 20 eletrões, perde imediatamente dois eletrões. Isto resulta em um catião com 20 protões, 18 eletrões, e carga 2+. Ele tem o mesmo número de eletrões que os átomos do gás nobre precedente, árgon, e é simbolizado como Ca2+. O nome de um ião metálico é o mesmo que o nome do átomo metálico a partir do qual se forma, pelo que o Ca2+ é chamado de ião de cálcio.

Indo do lado direito para o esquerdo na tabela periódica,  átomos de elementos não metálicos ganham geralmente eletrões suficientes para ficarem com o mesmo número de eletrões que um átomo do gás nobre seguinte na tabela periódica. Eles formam aniões com uma carga negativa igual ao número de grupos à esquerda dos gases nobres. Por exemplo, átomos de elementos do grupo 17 (um grupo à esquerda dos gases nobres)  ganham um eletrão e formam aniões com carga 1−; átomos de elementos do grupo 16 (dois grupos à esquerda) ganham dois eletrões e formam iões com carga 2−, e assim por diante. Por exemplo, o átomo neutro de bromo, com 35 protões e 35 eletrões, pode ganhar um eletrão para ficar com 36 eletrões. Isso resulta em uma anião com 35 protões, 36 eletrões, e carga de 1−. Tem o mesmo número de eletrões que átomos do gás nobre seguinte, o criptónio, e é simbolizado como Br−.

A tendência entre a carga do ião e a posição do grupo na tabela periódica pode ser utilizada como guia em muitos casos. No entanto, o seu valor preditivo diminui quando se vai para o centro da tabela periódica. Os metais de transição e alguns outros metais exibem frequentemente cargas variáveis que não são previsíveis pela sua localização na tabela. Por exemplo, o cobre pode formar iões com carga 1+ ou 2+, e o ferro pode formar iões com carga 2+ or 3+.

Este texto é adaptado de <a href="https://openstax.org/books/chemistry-2e/pages/2-6-molecular-and-ionic-compounds">Openstax, Chemistry 2e, Section 2.6: Molecular and Ionic Compounds</a>.

Iões e Cargas Iónicas

Nas reações químicas comuns, o núcleo - que contém os prótons e nêutrons de cada átomo e, portanto, identifica o elemento - permanece ...

Education

JoVE Core

Chemistry

Química

Atoms and Elements

Átomos e Elementos

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

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 - Química dá vida a conceitos gerais de química usando vídeos de animação fáceis de entender. Além disso, nos vídeos Cientistas em ação, demonstramos experimentos de pesquisa clássicos e originais realizados atualmente por cientistas em laboratórios em todo o mundo.

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

Description

Transcript

Tags

More videos by Standards