Introducing KNOVA — A free reading app with curriculum-aligned passages on History & Science for Grades 3-8Learn More →

What is an Ionic Bond? — Reading Comprehension

No ratings yet

Premium Resource

Grades

Rate this resource

Send Feedback / Report an Issue

About This Reader

This science reading passage provides a clear and engaging explanation of ionic bonds for a middle school audience. It defines ionic bonds as the result of electron transfer between atoms, leading to the formation of positively charged cations and negatively charged anions. The passage uses relatable examples like table salt (sodium chloride) to illustrate the concept. It also highlights the properties of ionic compounds, such as their high melting points and conductivity when molten or dissolved. The content aligns with NGSS standards related to the structure and properties of matter (MS-PS1-1), fostering a deeper understanding of chemical bonding in everyday substances.

CONTENT PREVIEW

This illustration depicts the formation of an ionic bond between a sodium atom and a chlorine atom, showcasing the transfer of an electron and the resulting attraction of oppositely charged ions to form sodium chloride (table salt).

An ionic bond is a fundamental type of chemical bond formed by the electrostatic attraction between oppositely charged ions. This bond results from the complete transfer of one or more electrons from one atom to another. The formation of ionic bonds is driven by the atoms' tendency to achieve a stable electron configuration, typically a full outermost electron shell.

The process begins with the formation of ions. Atoms that readily lose electrons are typically metals (like sodium) and become positively charged ions, known as cations. Conversely, atoms that tend to gain electrons are usually nonmetals (like chlorine) and become negatively charged ions, called anions. The electrostatic force of attraction between these oppositely charged cations and anions is what constitutes the ionic bond.

A classic example of an ionic bond is the formation of sodium chloride (table salt). A sodium atom (Na), a metal, has one electron in its outer shell. It transfers this electron to a chlorine atom (Cl), a nonmetal, which needs one electron to complete its outer shell. This transfer results in a stable, positively charged sodium cation (Na+) and a stable, negatively charged chloride anion (Cl−). The powerful electrostatic attraction between these two ions forms the ionic bond in the compound NaCl.

Ionic compounds, such as sodium chloride, exhibit several distinct properties due to the strength of their ionic bonds. They typically form crystalline solids with ordered structures and possess very high melting and boiling points. This is because a significant amount of energy is required to overcome the strong electrostatic forces holding the ions together. Furthermore, while ionic compounds are poor conductors of electricity in their solid state, they become excellent conductors when melted or dissolved in water, as the ions are then free to move and carry an electrical charge.

Fun Fact: Every single atom in a giant crystal of table salt (sodium chloride) is held in place by an ionic bond, creating a repeating 3D lattice structure.

What is the primary characteristic of an ionic bond?

Sharing of electronsTransfer of electronsWeak attraction between atomsFormation of neutral atoms

What type of ion is formed when an atom loses electrons?

AnionCationMoleculeCompound

Which type of element typically forms cations in an ionic bond?

NonmetalsMetalsNoble gasesHalogens

What is the name of the negatively charged ion formed when a chlorine atom gains an electron?

ChlorateChlorideChlorine ionChlorite

Why do atoms form ionic bonds?

To become largerTo change colorTo achieve stabilityTo become less reactive

Which of the following is a common property of ionic compounds mentioned in the passage?

Low melting pointsGaseous at room temperatureGood conductors when moltenSoft and easily broken

What is the main idea of this reading passage?

All chemical bonds involve electron sharing.Ionic bonds are only found in living organisms.Ionic bonds involve electron transfer to form charged ions.Metals are always negatively charged.

If an atom of potassium (a metal) reacts with an atom of fluorine (a nonmetal), what type of bond is most likely to form?

Covalent bondMetallic bondIonic bondHydrogen bond