Chemical Bonding

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Chemical Bonding

What do I need to remember? • Valence electrons are electrons on the outer most energy level of the atom • Noble gases are stable (the elements in group 18) • All atoms would be more stable if they had this eight (or two) valence electrons • Two electrons are in the outside energy level of a stable helium structure • Eight electrons are in the outside energy level for the other noble gases

Group

Family Name

1 2

Alkali metals Alkaline Earth metals

13 14 15 16 17 18

Oxygen group Halogens Noble gases

# valence electrons 1 2

3 4 5 6 7 8

Why do atoms chemically bond? • Atoms bond chemically to become more stable • To become more stable, atoms want to have either two or eight valence electrons.

• Group 1 and Group 2 metals tend to transfer electrons to Group 16 or Group 17 nonmetals to form ionic bonds.

How do Metals and Nonmetals Differ? • Metals tend to lose electrons to achieve a stable noble gas structure • Nonmetals tend to gain electrons to achieve a stable noble gas structure • When a metal loses an electron and a nonmetal gains that electron they bond and become stable through ionic bonding • Nonmetals bond with each other by sharing electrons to become stable through covalent bonding

What elements are bonded together?

What type of bond is this?

What type of bond is this?

What type of bonds are in sugar?

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QuickTimeª and a Sorenson Video decompressor are needed to see this picture.

Practice • • •

What is the difference between an ionic bond and a covalent bond? When Na is bonded to Cl what type of bond do you have? When two H atoms are bonded to one O atom what type of bond do you have?