Ionic and Covalent Bonds

Ionic and Covalent Bonds

Middle School

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Learning Objectives

• Define chemical bonding and understand why atoms form bonds with each other.

• Describe how ionic bonds are formed when atoms transfer their electrons.

• Describe how covalent bonds are formed when atoms share their electrons.

• Explain the difference between ionic and covalent bonds using some common examples.

Key Vocabulary

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Ion

An atom that has gained or lost electrons, giving it a positive or negative charge.

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Molecule

A group of two or more atoms held together by chemical bonds to form a substance.

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Ionic Bond

A chemical bond where one atom transfers its electrons to another, creating charged ions.

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Covalent Bond

A chemical bond formed when two atoms share one or more pairs of their electrons.

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What is an Ionic Bond?

• An ionic bond is the attraction between two oppositely charged ions.

• These bonds form when one atom transfers its electrons to another atom.

• This electron transfer creates a very strong and stable chemical link.

• For example, lithium gives an electron to fluorine to form lithium fluoride.

Multiple Choice

How is an ionic bond formed between two atoms?

• By transferring electrons from one atom to another.

• By sharing electrons to create a stable link.

• By combining the nuclei of the two atoms.

• By destroying electrons in one atom.

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What is a Covalent Bond?

• A covalent bond is formed when atoms share one or more electrons.

• This sharing of electrons creates a strong connection that holds the atoms together.

• These bonds are common in organic compounds that are essential for life.

• In methane (CH₄), carbon shares electrons with four hydrogen atoms.

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Multiple Choice

What is the primary characteristic of a covalent bond?

• One atom gives electrons to another.

• Atoms share electrons with each other.

• They are easily broken.

• The atoms have opposite charges.

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Common Misconceptions About Chemical Bonds

Misconception	Correction
Atoms can only form one type of bond.	Complex molecules can have different types of bonds, like ionic and covalent.
Electrons are lost or destroyed during bonding.	Electrons are only transferred or shared between atoms, never destroyed.
Bonds are just atoms ‘sticking’ together.	Bonds are specific electrochemical interactions to achieve stability.

Multiple Choice

What is the key difference in how electrons behave in ionic versus covalent bonds?

• Electrons are not involved in covalent bonds.

• Electrons are transferred in ionic bonds and shared in covalent bonds.

• Electrons are shared in ionic bonds and transferred in covalent bonds.

• Electrons are destroyed in ionic bonds and created in covalent bonds.

Multiple Choice

What happens when lithium reacts with fluorine to form lithium fluoride (LiF)?

• Lithium shares electrons equally with fluorine

• Lithium gains an electron from fluorine

• Lithium transfers an electron to fluorine, forming oppositely charged ions

• Lithium and fluorine form a molecule by sharing a pair of electrons

Multiple Choice

A molecule is formed where electrons are shared between atoms, and it requires a lot of energy to break the bonds. What type of compound is this most likely to be?

• An ionic compound

• An organic compound with covalent bonds

• A noble gas

• A metallic compound

Multiple Choice

Based on the formation of lithium fluoride, what would you predict happens when a metal and a non-metal react?

• They will likely form a covalent bond by sharing electrons.

• They will not react or form any bonds.

• They will likely form an ionic bond by the metal transferring electrons to the non-metal.

• They will both become negatively charged ions.

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Summary

• Chemical bonds join atoms to create stable molecules.

• Ionic bonds involve the transfer of electrons between atoms.

• Covalent bonds involve the sharing of electrons between atoms.

• Molecules can sometimes have more than one type of bond.

Poll

On a scale of 1-4, how confident are you about differentiating between ionic and covalent bonds?

• 1

• 2

• 3

• 4