Finals M4 Chemistry covalent,ionic,metallic

​Covalent Bonds

Covalent bonding occurs in elements and compounds containing non-metallic elements only and is formed when pairs of electrons are shared.

A shared pair of electrons is known as a single bond.

All which form a covalent bond join together to form uncharged molecules. All the atoms involved achieve a full outer shell of electrons.

for Hydrogen, it has only 1 electron which make it share the only electron. The total electrons after bonded for hydrogen is only 2 electrons (duplet).

the rest atoms must be octet (8 electrons), but for period 3 and above, they can make more than 8 electrons.​

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1 electron shared by each hydrogen​

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​Hydrogen (H₂)

Cl₂ = 1 electron shared by each chlorine atom

H₂O = 1 electron shared by each hydrogen, to form two single covalent bonds​

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​Cl₂ and H₂O

THREE electrons are shared by two atoms

e.g. N₂​

​Triple bonds

TWO electrons are shared by two atoms​

e.g. CO₂​

​Double bonds

​Double Bonds and Triple bonds

Covalent Bond

Electron Dot or Lewis Dot

signifies the bonding pair of electrons

Polyatomic ions

a bonded set of 2 or more atoms that function as a single unit

Octet Exceptions

Free Radicals have odd number of electrons

Octet exceptions

electron deficient the central atom does not have a filled valence shell

Multiple Choice

What type of bond is shown in this image?

• Ionic
• Polar Covalent
• Nonpolar Covalent
• Van der Waals Force

Multiple Choice

What two types of atoms make a covalent bond?

• 2 Nonmetals
• 1 Nonmetal and 1 Metal
• 2 Metals
• 2 Noble Gases

Multiple Choice

How do covalent bonds form?

• Donating & receiving valence e- between atoms.
• Opposite slight charges attract each other between compounds.
• Scientists are still not sure how they form.
• Sharing valence e- between atoms.

Multiple Choice

Compared to ionic compounds, molecular compounds generally have...

• stronger chemical bonds
• poor conductivity
• a high melting point
• lower densities

Multiple Choice

Partial charges like the ones shown here are called:

• dipoles
• deltas
• ions
• magnetic poles

Multiple Choice

In this Lewis structure, the symbol above F means...

• electrons are being transferred to Fluorine
• electrons are less attracted to F than H
• electrons are more attracted to F than H
• Fluorine has formed a cation

Multiple Choice

Electronegativity is a measurement of the ability of a nucleus to...

• attract bonding electrons
• attract other nuclei
• attract elenece in the non-valence energy levels

Multiple Choice

Covalent bonds are between...

• Metal and Non-metal
• Non-metal and Non-metal
• Metal and Metal

Multiple Choice

Valence electrons are found

• in the innermost energy level of an atom

• in the middle energy levels of an atom

• in the outermost energy levels of an atom

Multiple Choice

In an electron dot diagram, two pairs of shared electrons represents a ...

• single bond
• double bond
• triple bond
• quadruple bond

Ionic bonds

THe CATion transfers valence electrons to the Anion. A a Crystalline lattice holds it together.

Ionic bonds

How can you tell if it is an Ionic bond?

You look for the Metal!!! A Metal and a non metal is required to make an Ionic bond.

This is also called a SALT.

Ionic bonds are strong

Salts have very high melting points. This means that you need a LOT of heat to melt salt. Think of your French fries. The salt is a crystal not a puddle.

Multiple Choice

What temperature do Ionics melt?

• Very low temperatures

• They don't ever melt

• Very high temperatures

• They always melt

Ionic bonds

• Are good conductors

• But ONLY WHEN dissolved in water!!!

• (aq) aqueous mixture

When a salt dissolves in water (aq)

IONS are FREE to MOVE!!

THE MORE FREE MOVING IONS

• the Brighter the light!!!!!!!!!

• This is called an ELECTROLYTE

Multiple Choice

When do Ions conduct electricity?

• When they are in a crystal structure

• When they are free moving in solution

• When they are solids

• When they are bonded together.

Multiple Choice

Which pair of atoms will form an ionic bond?

• Li and Ne

• K and Br

• K and Cs

• S and Cl

Multiple Choice

Which pair of atoms will form an ionic bond?

• Li and Be

• Na and Mg

• K and Ca

• Na and Cl

Multiple Choice

An ionic bond would form between Sc and F

• True

• False

Multiple Choice

Which of the following compounds would you expect to be ionic?

• H2O

• CO2

• SrCl2

• SO2

Multiple Choice

Which of the following compounds would you expect to be ionic?

• CO

• NO

• LiCl

• SiO2

Octet Rule

elements tend to bond in such a way that each atom has eight electrons in its valence shell

Ionic Bonds

metal and non metal

Ionic Bonds

complete transfer of electron

Ionic Bond

Forms cation and anion that are held together due to electrostatic attraction forces

Multiple Choice

Chemical bond is ...

• the physical mixing of two different atoms.

• the force that holds two atoms together

• the energy used up when two atoms combined.

• the temperature that changes the phase of matter.

Multiple Choice

Predict the bond that will form between Sr and S.

• Ionic

• Covalent

Multiple Choice

Predict the bond that will form between Be and F.

• Ionic
• Covalent

Multiple Choice

The octet rules states that most elements want to have _____ valence electrons.

• 2

• 4

• 6

• 8

Multiple Choice

If an atom gains two electrons what charge will it have?

• -2

• -1

• +1

• +2

Multiple Choice

If an atom loses two electrons what charge will it have?

• -2
• -1
• +1
• +2

Multiple Choice

What kind of bond forms when atoms exchange electrons?

• ionic
• covalent
• artificial
• univalent

Multiple Choice

What is the name for an ion with a negative charge?

• cation
• anion
• onion
• union

Multiple Choice

What is the name for an ion with a positive charge?

• cation
• anion
• onion
• union

Multiple Choice

Ionic bonds are between...

• nonmetals and nonmetals
• carbon and oxygen
• metals and nonmentals
• hydrogen and chlorine

Multiple Choice

What is a valence electron?

• The sum of neutrons and protons.
• The # of electrons in the last shell.
• A type of bond.
• A popular compound.

Multiple Choice

Why do elements bond?

• To be friends

• To create a new element

• To become stable

• To get bigger

Multiple Choice

There are more metals than non metals in the periodic table.

• True
• False

Multiple Choice

At room temperature, most metals are

• liquid
• solid
• gas
• an alloy

Multiple Choice

Metals are hard because metals have a

• sea of electrons that tightly hold the nuclei together

• they form triple bonds

• low melting point

• high luster

Multiple Choice

Why are metals malleable?

• The metal ions can easily slide past one another

• The metal ions cannot easily slide past one another

• The metal ions repel one another

• The metal ions attract one another

Multiple Choice

What does malleable mean?

• Breaks easily

• Always stays in the same shape

• Can be drawn into wires

• Can be forced into a certain shape without breaking

Multiple Choice

Metals conduct electricity because

• the metal ions are free to travel

• their electrons are free to travel

• the bonds between metal atoms can easily be broken

• of witchcraft

Multiple Choice

Which of the following would be held together by the metallic bond?

• Atoms of iron (Fe)

• Molecules of CH₄

• Atoms of sulfur (S)

• Units of NaCl

Electrons are the Key

• If valence electrons are shared by atoms, it is called COVALENT bonding

• If valence electrons move freely between atoms, it is called METALLIC bonding

• If valence electrons are transferred from one atom to another, it is called IONIC Bonding

ELECTRONEGATIVITY

• DEN Range is the difference in electronegativity values between atoms

• Determines the type of bond

• Covalent bonds have similar electronegativities

• Ionic bonds have different electronegativities

What you need to remember...

• Metals + Nonmetals

• Make IONIC bonds

• Transfer electrons

• High electronegativity difference

Ionic Bonds

• Form Crystalline Lattice (crystals)

• Have high melting and boiling points

• Hard

• Brittle

• Conduct electricity when dissolved in water

What you need to remember

• Nonmetal + Nonmetal

• Make COVALENT bonds

• Share electrons

• Low electronegativity difference

Covalent Compounds

• Have Lower melting and boiling points

• Tend to be flammable

• When dissolved in water they do not conduct electricity

• Soft or brittle solid

• Can also form crystals

What you need to remember

• Metal ions near each other share valence electrons

• These valence electrons flow freely between all of the ions

• These delocalized electrons are why metals conduct heat and electricity

• It is also why metals are malleable and ductile

Metallic Bonds

• good conductors of heat and electricity

• malleable and ductile

• lustrous

• opaque

Multiple Choice

Identify the following compound as ionic or covalent: Na₂SO₄

• ionic

• covalent

Multiple Choice

What type of bond involves the sharing of electrons between atoms?

• covalent bond

• ionic bond

• metallic bond

• transfer bond

Multiple Choice

Identify the following compound as ionic or covalent: CF₄

• ionic

• covalent

Multiple Choice

A bond between a nonmetal and a nonmetal is called a(n)

• covalent bond

• ionic bond

• metallic bond

• transfer bond

Multiple Choice

Identify the following compound as ionic or covalent: MgO

• ionic

• covalent

​Polyatomic Ions

• ​Certain atoms bond covalently to form a group of atoms that have both molecular and ionic characteristics

• ​Polyatomic Ions: A charged group of covalently bonded atoms is known as a polyatomic ion

Multiple Choice

What is A charged group of covalently bonded atoms?

• A polyatomic ion

• A cation

• An anion

• a crystal ion