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Chemical Bonds Ionic and Covalent Bonding

Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

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Page 2: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Chemical Bonds– Ionic: Metals + Nonmetals

– Covalent: Nonmetals + Nonmetals• Sharing of electrons• Mostly gases, some liquids and

amorphous solids

– Metallic: • Metal atoms bonded to several other metal atoms

Page 3: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Ionic Compounds *

Page 4: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Properties of Ionic Compounds

• At room temperature, most are cystalline solids

• Very attractive forces

Page 5: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Ionic Compounds (Salts):• Composed of a Metal ion (cation, M+) combined with an Non-

Metal ion (anion, N-); atoms exchange transfer electrons.• Are Crystalline Solids. • Have high melting points• Smallest component particle is called a formula unit, not a

molecule.

Cations

Anions

Page 6: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Types of Ions

• Monoatomic ion has only one atom examples are chloride, Cl-, fluoride, F-, sodium Na+

• Polyatomic ion has more than one, ex. sulfate (SO4

2-), nitrate (NO3-)

Page 7: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

What is the octet rule???

• Octet Rule says that atoms tend to gain, lose or share electrons so as to have eight electrons in their outer electron shell

Page 8: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

• Composed of a Non-Metal combined with another Non-Metal.

• Are mostly gases, liquids, and sometimes amorphous solids.

• Have low melting points• Bonded atoms share electrons.

Covalent (Molecular) Compounds:

H2O(s)

*

H2O(l)

H2O(g)

Page 9: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Covalent Bonding• Equal & Unequal sharing of electrons:

Electronegativity, Polarity and Miscibility

• Representation of covalent bonding using

Lewis Structures

• Energetics

Page 10: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Polar vs. Non-Polar

• Polar:– A type of covalent bond

in which the electrons are NOT shared equally.

– When atoms of different electronegativities form a bond, the electrons tend to be more controlled by the atom with the higher electronegativity.

Page 11: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Non-Polar

• A non-polar bond is one in which the electrons are shared equally.

• Covalent bond that has no positive or negative 'ends'.

Page 12: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

What are single, double, and triple bonds??

• ONLY refers to covalent bonds• A single bond is a bond in which two atoms

share a pair of electrons.• A double bond is a bond that involves two

shared pairs of electrons.• A triple bond is a bond that involves three

shared pairs of electrons

Page 13: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

Bonding Theories

(1) Valence Shell Electron Pair Repulsion (VSEPR) Theory: considers only the valence electrons and their geometry when they repel each other when they form bonds.

“The best arrangement of a given number of electron domains is the one that minimizes the repulsions among

them.”

Page 14: Chemical Bonds Ionic and Covalent Bonding. Chemical Bonds – Ionic: Metals + Nonmetals – Covalent: Nonmetals + Nonmetals Sharing of electrons Mostly gases,

VSEPR Theory• Based on Lewis structures we can know the

shape or “geometry” of molecules

• VSEPR (pronounced “vesper”) stands for Valence Shell Electron Pair Repulsion

• Electrons around the central nucleus repel each other. Thus, resulting structures have atoms maximally spread out