Chemical Bonding

Chemistry: Unit 4

What is a Chemical bond?

A force/mutual electrical attraction that holds atoms together in a substance

What is Electronegativity?

A measure of the ability of an atom in a bond to attract electrons

What is the Octet rule?

The tendency of atoms to prefer to have 8 valence electrons

What is a Molecule?

Compound formed when 2 or more elements are covalently bonded

What is Salt?

A binary ionic compound between 1 kind of metal atom and 1 kind of nonmetal atom

What is Crystal lattice?

Network of cations and anions that are mutually attracted to one another

What is it when forces are between different substances?

Intermolecular

What is it when forces are within the same substances

(chemical bonds)?

Intramolecular

What is meant by the statement, “Bonding

is a spectrum.”?

There aren’t just two types of bonds. It is a spectrum with ionic and nonpolar covalent at the two extremes.

Write a sentence to summarize the connections

between chemical bonds, chemical reactions, and

compounds.

Chemical bonds form through chemical reactions and

result in new compounds.

Explain why most atoms form chemical bonds.

They form bonds to be stable with full outer energy levels of electrons.

Explain why some atoms don’t form chemical bonds.

Noble gases don’t form chemical bonds because they are already stable.

What does the Chemical Formula tell you about an Ionic compound?

It represents the ratio of cations to

anions in the crystal lattice.

What does the Chemical Formula tell you about an Covalent compound?

The chemical formula tells you exactly the number and types of atoms.

In what bond are Electrons transferred?

Ionic Bonds

In what bond are Electrons shared?

Covalent Bonds

What can Ionic bonds result in?

Formation of a Salt

What do Covalent bonds result in?

Formation of a Molecule

Ionic bonds are always between _________.

Ions

Covalent bonds can be __________ or ___________ .

polar; nonpolar

Ionic Compounds have _______ melting and boiling points.

High

Ionic compounds are what?

Crystalline solids

Ionic Compounds ______ conduct electricity when

dissolved in water.

Can

Covalent Compounds can be what?

Solid, liquid, or gas

Covalent Compounds have _______ melting and boiling points.

Low

Covalent Compounds ______ conduct electricity when

dissolved in water.

Cannot

What is an Ionic compound?

A compound made of positive and negative ions that chemically bond in a way that the charges equal out.

What is an Ionic bond?

Formed when electrons are transferred from the cation to the anion

Whats an Ion?

Charged atoms

What is a Cation?

Positively charged atom from losing electrons

What is an Anion?

Negatively charged atom from gaining electrons

What is a Polyatomic ion?

A positively or negatively charged, covalently bonded group of atoms

What is a Transition metal?

Metals that “transition” because they can form many different ions

Explain the connection between electronegativity

and the formation of an ionic bond.

The difference in electronegativity is so great that one atom takes the electrons from the other because it has such a greater attraction to them.

Use an example of an ionic compound to explain

the “rule of zero charge”.

MgCl2 is one atom of magnesium with a 2+ charge, and two atoms of chlorine, each with a 1- charge. 1(2+) + 2(1-) = 2+ + 2- = 0

What are Binary ionic compounds?

made of 2 elements that transfer e- in an ionic bond

What are Compounds with polyatomic ions?

made of one (or more) covalently bonded charged group of atoms that transfer e- in an ionic bond.

What are Binary molecular compounds?

made of 2 elements that share e- in a covalent bond

Explain why it is necessary to include a Roman

numeral when naming an ionic compound with a

transition metal.

You cannot determine the charge of a transition metal from the periodic table, so the Roman numeral is necessary to indicate the charge of the metal ion.

What is a Metallic bond?

An interaction that holds metal atoms together through a shared pool of valence electrons

What are Delocalized electrons?

Electrons not associated with a single atom or bond

What is an Alloy?

A solution of two metals mixed together

Explain what makes a metallic bond different from

an ionic compound.

They are different because they do not lose their valence electrons, instead they share.

Explain what makes a metallic bond different from

a covalent compound.

They are different from covalent because they do not result in a compound being formed.

Explain why the “sea of e-” forms in metallic bonds and why this makes them good electrical conductors.

Forms because metals like to form lattices, but they are often bigger so their orbitals overlap. They also have lower electronegativities so their attraction for electrons in a bond is lower.

Because of this, the electrons are delocalized, making them good at creating a flow of e- when conducting electricity.

What is a Covalent compound?

A compound formed when two or more atoms share

electrons

What is a Covalent bond?

The bond between nonmetallic atoms that share electrons

What is a Molecule?

A neutral group of atoms held together by covalent bonds

What are Diatomic elements?

When 2 atoms of the same element exist naturally as a molecule

Explain the connection between electronegativity

and the formation of a covalent bond.

When the electronegativity difference is small, and thus not big enough for one atom to take the electrons from the other, the atoms share instead of transfering

Differentiate between polar covalent and nonpolar

covalent bonds.

Polar covalent are when electrons are unequally shared. Nonpolar covalent are when electrons are equally shared, and the difference in electronegativity is 0.

Explain how the VSEPR theory impacts how you

draw Lewis structures for molecular compounds.

VSEPR theory is the tendency for electron pairs to be as far apart as possible from one another, and thus when you draw Lewis structures for molecular compounds, you should draw them in a way that spaces them out as much as you can.