Phys. Science 4-2: Types of Bonds

​Types of Bonds

Multiple Choice

Valence electrons are the

• Outermost electrons in an atom

• Total electrons in an atom

• Innermost electrons in an atom

• Smallest electrons in an atom

Multiple Choice

Which of the following elements has 5 valence electrons?

• boron

• phosphorus

• magnesium

• chlorine

Multiple Choice

This could be the dot diagram for...

• He

• Al

• Be

• Si

Multiple Choice

How many valence electrons does Carbon have?

• 4
• 12
• 6
• 14

Lesson Objectives

• Describe Ions and how they form

• Distinguish between Ionic, Covalent, and Metallic Bonds

• Predict what sort of bond will form based on the types of elements involved

​Different Types of Bonds

• There are three different types of bonds that can form between elements

  • Ionic

  • Covalent

  • Metallic

What are Ions?

• Recall: Electrons have a negative charge, and protons have a positive charge

  • Normally, the two are balanced in an atom, and it is neutral

• When atoms are exposed to enough energy, they can gain or lose electrons

• Ion: A charged particle that forms when an atom or group of atoms gains or loses one or more electrons

  • ions can be positive or negative, depending on whether they gain or lose electrons

    • Ions take the shortest route to having a filled shell

      • It is easier to lose one or two electrons than to gain 7 or 6

How do Ionic Bonds Form?

• Ionic Bonds: The attractive force between oppositely charged ions, which form when electrons are transferred from one atom to another

  • One atom is "stronger" than the other and takes electron(s) from it, dragging the rest of the atom along with it

    • Takes electrons until it has a full outer energy level with 8 electrons

• Ionic Bonds create Ionic Compounds

How do Positive Ions form?

• Positive charges form when an atom loses an electron

  • It now has more protons than electrons and is positively charged

• Cation: A positively charged ion

  • In General, Metals lose electrons and form cations

• Forming cations requires energy to lose the electrons

How do Negative Ions form?

• The electrons that metals lose have to go somewhere

• Nonmetals will pick up the electrons and use them to fill their outermost energy level

  • Now have more electrons, so they have a negative charge

• Anions: Ions that have a negative charge due to having more electrons than protons

• In General, Nonmetals form anions

  • When an atom becomes an anion, we change the name so the element name ends with -ide

    • Chloride, Bromide, Oxide

How do Ionic Compounds form?

• Ionic Compounds form when positive cations are attracted to negative anions

  • A cation is able to give enough electrons to fill the outer energy level of the anion

  • The ending compound is neutral because the positive and negative charges cancel out

• Ionic compounds only form between a metal and a nonmetal

Properties of Ionic Compounds

• Ionic Compounds form hard solids called crystals

  • Have flat faces and straight edges

• Crystal Lattice: The regular pattern in which a crystal is arranged

  • Positive and negative ions form a repeating Three-Dimensional shape

• Ionic Compounds are Brittle

• Ionic Compounds have high Melting points and dissolve in water

  • When dissolved, they can conduct Electricity

Multiple Choice

Why do atoms form Ions?

• Atoms form ions to emit radiation.
• Atoms form ions to increase their mass.
• Atoms form ions to achieve stability by gaining or losing electrons.
• Atoms form ions to create new elements.

Multiple Choice

If an atom loses electrons, the charge will be positive.

• true

• false

Multiple Choice

What is a positive ion called?

• anion

• cation

• isotope

• covalent

Multiple Choice

What is a negative ion called?

• anion

• cation

• covalent

• isotope

Multiple Choice

How are ionic bonds formed?

• Transfer of electrons
• Sharing of electrons
• Merging of Electrons

• Destruction of electrons

Multiple Choice

Ionic Bonds form between....

• metals and nonmetals

• nonmetals and nonmetals

• metals and metal

Multiple Choice

Ions are: 

• atoms with a positive or negative charge
• atoms with no charge
• atoms with ONLY a positive charge
• atoms with ONLY a negative charge

Multiple Choice

An atom with 3 valence electrons "wants" a full shell, so it can either gain 5 or lose 3. Which is more likely to occur?

• It will Gain 5

• It Will Lose 3

• Nothing

What are Metallic Bonds?

• Metals can form bonds with other metals

• Metallic Bond: A bond formed by the attraction between positively charged metal ions and the electrons around them

  • Metal atoms can move close enough together that their electron energy levels overlap, allowing electrons to travel from atom to atom

  • Give metals their unique properties

    • shiny

    • Able to conduct heat and electricity through the movement of electrons

    • Ductile and Malleable

What are Covalent Bonds?

• Covalent Bond: A bond formed when atoms share one or more pairs of electrons

  • Atoms merge close enough that they can share the electrons equally between their outermost energy level

• Form between the atoms of Nonmetals

What are Molecules

• Molecule: A group of atoms that are held together by chemical forces

  • The smallest unit of matter that can exist by itself and retain all of a substance's chemical properties

• Molecules contain at least two atoms bonded by a covalent bond

• Most molecules are made of two or more elements, but some are made of two of the same element

Diatomic Molecules

• Diatomic Molecule: a molecule bonded by two of the same element

  • Mainly Halogens

  • Oxygen

  • Nitrogen

Counting Covalent Bonds

• Atoms can share one or more pairs of electrons at a time

  • More complicated molecules share more pairs of electrons

• Carbon is a unique atom because of its four valence electrons

  • Allows it to form four covalent bonds and make many complex molecules with different shapes

Properties of Molecules

• Most covalently bonded substances have: Low Melting/Boiling Points

  • Water is a major exception

• Many (But not all!!) are gases at room temperature

• Covalent solids tend to be soft

Multiple Choice

What two types of atoms make a covalent bond?

• 2 Nonmetals

• 1 Metal and 1 Nonmetal

• 2 Metals

• 2 Noble Gases

Multiple Choice

How do covalent bonds form?

• By donating and receiving valence electrons between atoms.

• Scientists still aren't sure.

• Opposite slight charges attract each atom in the compound.

• Sharing valence electrons between atoms

Multiple Choice

What kind of bond will form between Hydrogen and Oxygen?

• ionic

• covalent

• metallic

• no bond

Categorize

Options (15)

Electron Transfer

High Melting Point

Soluble in Water

Conducts Electricity in Solution

Formed Between Metals and Nonmetals

Shared Electrons

Low Melting Point

Poor Conductors of Electricity

Molecular Compounds

Conducts Electricity in Solid State

Malleable

Ductile

Luster/Shiny

Formed Between Metal Atoms

Formed between two Non-Metals

Organize these options into the right categories

Ionic Bonds

Covalent Bonds

Metallic Bonds