CHEMICAL BONDS AND STABILITY

Intro to Chemistry

How do atoms bond?

Atoms bond by or

electrons.

TRANSFERRINGSHARING

An atom’s depends on how likely it will .

STABILITY REAC

T

Why do atoms bond?

want to be therefore they want their energy filled.

ATOMSOUTER-MOST

STABLE

LEVEL

electrons (with the exception of having

electrons) make a

8 VALENCE HELIUM 2

VALENCESTABLE ATOM.

Atoms react or BOND in two ways:

1. An atom electrons to become

2. An atom electrons to become

LOSESPOSITIVE

GAINS

NEGATIVE

CHEMICAL BOND

The of that

FORCE ATTRACTION

HOLDS TWO ATOMS TOGETHER

Reactive Metals and Nonmetals

Elements that have react easily with whose atoms 1

Which group has 7 valence electrons?

Which group has 1 valence electron?

7 VALENCE ELECTRONSELEMENT

SGIVE UP OR SHARE ELECTRON

17 – very reactive

1 – very reactive

Reactive Metals and Nonmetals

Usually elements have , or

will their electrons.

Elements with , or will electrons.

1 2

3 VALENCE ELECTRONS

LOSE

5 67 VALENCE ELECTRONS

GAIN

Nonmetals

Have or more Bond with by

electrons. and

bond by electrons.

4 VALENCE ELECTRONSMETALS GAINING

NONMETALS NONMETALSSHARING

THERE ARE TWO TYPES OF BONDS

IONIC BONDS COVALENT BONDS

IONIC BONDS

Atoms transfer VALENCE ELECTRONS to reach stability.

**Atoms with 5, 6 or 7 valence electrons

** Atoms with 1, 2 or 3 valence electrons

GAIN ELECTRONS TO BE STABLE

LOSE ELECTRONS TO BE STABLE

Lithium, Fluorine, Neon

Lithium – Gives 1 Valence Electron Fluorine – Takes 1 valence electron to

become stable. Neon – does not take or give any

electrons. Neon is in group 18 and is already stable.

Ionic Bonds

When an atom or valence the becomes or electrically charged.

Ion -

LOSES GAINSELECTRONS

ATOMPOSITIVELY

NEGATIVELY

An atom or group of atoms that has an electric charge (+ or - )

LOSING VALENCE ELECTRONS GIVES YOU +++++POSITIVE IONS

LOSING VALENCE ELECTRONS GIVES YOU….

When an atom an it becomes charged.

WHY DOES THIS HAPPEN?

LOSES ELECTRONPOSITIVELY

+++ POSITIVE IONS+++

GAINING VALENCE ELECTRONS GIVES YOU…

---NEGATIVE IONS--

GAINING VALENCE ELECTRONS GIVES YOU…

When an atom an it becomes charged.

WHY DOES THIS HAPPEN?

---NEGATIVE IONS---GAINS ELECTRO

N NEGATIVELY

REVIEW: HOW IONIC BONDING WORKS

Atoms become charged Transferring valence electrons

cause ions to be formed Opposite ions attract each other

COVALENT BOND

A chemical bond formed when two atoms share electrons. (Uncharged)

***Covalent bonds usually form between and

. The of the

of each holds the together when

NONMETALS NONMETALSFORCE ATTRACTION

ATOMS NUCLEUSSHARING

ELECTRONS

COVALENT BOND

** A molecule is

**Remember** Atoms bond to reach (Helium 2 v.e.) which makes the

Molecular Compound: A that is of

A NEUTRAL GROUP OF ATOMS JOINED BY COVALENT BONDS.

COVALENTLY8 VALENCE ELECTRONS

COMPOUND STABLECOMPOUND

MADE MOLECULES COVALENTLY BONDED