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Topic 6: Bonding, Part 1 Page 2

Review Questions: Pg 99 (#1-5) and Pg 102 (#6-9)

Chemical Bonds (Page 98 in Review Book)

Bonds are energy relationships between atoms.

When a chemical bond is formed, the resulting compound has less potential energy then the original

substances

The formation of chemical bonds releases energy. (Exothermic):

Atom B + Atom C B/C +Energy

To break a chemical bond requires energy. (Endothermic):

B/C + Energy Atom B + Atom C

The greater the energy released during the formation, the more stable the compound is.

Lewis Electron Dot Structures (Page 99-102 in Review Book)

Made up of one symbol and up to 8 valence electrons

Group

Period

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Topic 6: Bonding, Part 1 Page 3

The Kernel (represented by the symbol) of every atom is positively charged.

The dots surrounding the kernel represent the valence electrons of each atom.

Use the last number of the electronic configuration to figure out how many valence electrons are in an

atom.

The Lewis structure of a Hydrogen Atom is simple:

H

When two hydrogen atoms combine to form the hydrogen molecule (H2), they share two electrons in

between them in a non-polar covalent bond:

H:H

Instead of using dots to show the pair of electrons, a single dash may be used to show the bond.

H-H

Some common bonds:

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Topic 6: Bonding, Part 1 Page 4

Review Questions: Pg 103 (#10-12)

Metallic Bonds (Page 102-103 in Review Book) 

Metallic atoms have few valence electrons and low ionization energies.

Metals are made up of closely packed cations (Positively charged Ions), rather than neutral atoms.

Metallic atoms that make up a metallic solid have a kernel which is arranged in the fixed position of a

crystalline lattice, while the valence electrons move freely throughout the crystal and do not belong to

any specific atom. (Mobile sea of electrons)

The Octet Rule (Page 103-104 in Review Book)

Basically, they want to become stable by getting 8 valence electrons and will share, gain or loseelectrons in order to get a complete octet (eight valence electrons)

Covalent Bonds (Page 104-105 in Review Book)

A Non-Polar covalent bond is when the attraction between two nuclei is equal causing the electrons to

be shared equally. (Occurs when the atoms have close or equal electronegativity values)

When there is a Polar Bond, the electrons spend more time around the atom

with the highest electronegativity.

A polar covalent bond involving Hydrogen with any of the three most electronegative elements of 

Nitrogen, Oxygen and Fluorine is especially strong and is called aHydrogen bond.

Polar Covalent Bond

Non-Polar Covalent Bond