Covalent Bonds

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Sharing is Caring

Ionic Vs. Covalent

In ionic bonds one atom will transfer electrons to another atom, and then both atoms will be electrically charged. Once charged they will be attracted to each other.

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♠ In covalent bonds two or more atoms will share electrons.

Covalent Bonds

Formed by two or more nonmetals.

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Uses prefixes in their names.

Look at a Covalent Bond

How many valence electrons does fluorine have?

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So fluorine only needs one electron to fill its valence level.

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Covalent Bonding

Fluorine will share its lone electron with other atoms that need electrons.

When they share electrons they will form a bond.

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Covalent Bonds

When two or more atoms are combined by an ionic bond they are called a compound or salt.

When two or more atoms are combined by covalent bonds they are called a molecule or molecular compound.

Making Molecules

• Covalent molecules follow the same rules as ionic molecules when it comes to filling the valence shell. They must have eight electrons.
• When determining the formula for molecules it may be easy to draw Lewis diagrams for bonding.

Predicting Formulas

• How many electrons does oxygen need to be stable?
• How many electrons does hydrogen need to be stable?
• Predict the formula for a molecule of hydrogen and oxygen if they were to bond.

• How many electrons does oxygen need to be stable?
• How many electrons does hydrogen need to be stable?
• Predict the formula for a molecule of hydrogen and oxygen if they were to bond.

H₂O

Predicting Formulas

• Predict the formulas for the following molecules.
• S and O P and Br
• C and F N and O
• N and H H and O
• Si and O Si and Cl

Diatomic Molecules

There are some atoms that will readily form bonds with the same atoms. These are called diatomic molecules.

The atoms that form these molecules are H, O, F, Br, I, N, Cl

An easy way to remember them is the word HOFBrINCl

♣ Prefixes ♥

Mono- 1

Di- 2

Tri- 3

Tetra- 4

Penta- 5

Hexa- 6

Hepta- 7

Octa- 8

Nona- 9

Deca- 10

Naming Covalent Compounds

• When Naming Covalent molecules you name the first atom as you normally would.
• For the second atom you put the prefix for the number of atoms present as well as the name for the atom as a negative ion.
• *If the first atom has more than one atom present then it should be named with a prefix.

Naming

• OF₂
• To name the molecule above apply your rules
• You would name the first part oxygen as you normally would.
• For the second part you have 2 atoms so you would use the prefix di- and then fluoride. Oxygen difluoride

Naming

Try naming the molecules below.

SO₂ PBr₃

CF₄ N₂O

NH₃ H₂O

SiO₂ SiCl₄

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Answers

Sulfur dioxide Phosphorus Tribromide

Carbon tetrafluoride Dinitrogen monoxide

Nitrogen Trihydride Dihyrdogen monoxide

Silicon dioxide silicon tetrachloride

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Acids

• An acid is anything that can lose an H in a reaction.
• Acids are dissolved in water, and are usually denoted with the symbol (aq) behind them.
• There are different rules for naming acids.

Binary Acids

1) Name H hydro-

2) Name anion

3) Drop –ide and add –ic

4) Add the word acid

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Ex. HCl

hydro-chloride 🡪 hydrochloric acid

Binary Acids

H₃P

hydro-phosphide 🡪 hydrophosphoric acid

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HI

hydro-iodide 🡪 hydroiodic acid

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Oxy Acids

1) DO NOT NAME HYDROGEN!!

2) Name the polyatomic ion

3) ate 🡪 ic

ite 🡪 ous

4) Add the word acid

H₂SO₄

Sulfate 🡪 sulfuric acid

Oxy Acids

H₂SO₃

Sulfite 🡪

Sulfurous acid

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HBrO₃

Bromate 🡪

Bromic acid