bellringer!!! you have 5 minutes left!

BELLRINGER!!!

YOU HAVE 5 MINUTES LEFT!DIVIDE YOUR

NOTECARD INTO 4 SECTIONS AND COMPLETE THE

FOLLOWING CHART ACCORDING

TO THE NUMBER OF VALENCE

ELECTRONS EACH HAS.

Sulfer Cesium

Boron Silicon

Ex: ChlorineCl

BELLRINGER!!!





ELECTRONS EACH HAS.

Sulfer Cesium

Boron Silicon

Ex: ChlorineCl

Ionic and Covalent Bonding

PAGE 71

Atoms gain, lose or share electrons to gain EIGHT electrons in their valence shell so they can be stable.

Remember the octet rule?

form when atoms lose or gain electrons.

Metals + Nonmetals

For example: Sodium (Na) has 1 valence electron (group 1).

What happens if that 1 valence electron is taken away?

Ionic Bonds

Na 3rd E.L.

When Na loses that 1 valence electron, its 2nd E.L. becomes the outermost E.L..

Now the Na atom has a valence shell with 8 electrons and is stable.

Lost an electron?

Remember the octet rule?

Gone...

When the Na atom loses an electron, it has one less negative charge compared to the positive charges (protons), so...

….it now has an extra positive charge.

When an atom has an electrical charge (positive or negative).

What is an ion?

Chlorine has valence electrons

If Cl gains 1 electron, it will have 8 valence electrons and it will be stable (but it will have an overall negative charge).

More octet rule... Cl

7

Now Na has a positive charge (lost an electron) and Cl has a negative charge (gained an electron). What happens now?

Opposite charges attract, so Sodium and Chlorine will form an IONIC bond.

Compound name: Sodium Chloride (overall neutral charge)

Wanna bond?

Na+ Cl-

NaCl

form when atoms share an electron to gain eight valence electrons (octet rule).

Nonmetals + Nonmetals

Metals + Metals

For example, Chlorine has 7 valence electrons...

Covalent Bonds

Cl ClTwo chlorine

atoms share a pair of

electrons to form a covalent

bond

When atoms of the same type form a covalent bond:

Examples: H2 Cl2 O2 Br2

F2 I2 N2

What is a diatomic molecule? Cl Cl

Water is 2 Hydrogens (group 1: 1 valence electron) and 1 Oxygen (group 6: 6 valence electrons) COVALENTLY bonded together:

What about H2O?

H

H

O OHH

(H2O)

Remember…you should write 5 things you learned in complete sentences.

Summarize!!!!!

You have 3 minutes left.


Summarize!!!!!

You have 2 minutes left.


Summarize!!!!!

You have 1minute left.

Terms: Ionic and CovalentCircle your understanding of this word. (one is the lowest; 4 is the highest)

Use your notes for this definition!

Draw a description of this word

This is YOUR description of the word! How are you going to remember this word???

Writing a reaction

To show how atoms bond, we can write a chemical reaction:

1. Reactants on the left2. Products on the right3. Arrow means “yields” or “gives”

2H + O H2O

How to write a chemical reaction?

General Rule:Ionic Bonds: metal/nonmetalCovalent: 2 nonmetals

How can you tell the difference between ionic and covalent bonds?

Electronegativity

Sometimes electrons in covalent bonds are not shared equally by the two atoms.

Electronegativity is the attraction an atom has for a shared pair of electrons.

Elements in group 17 have the highest electronegativity, whereas elements in group 1 and 2 have the lowest electronegativity.

Atoms with high electronegativity tend to want to gain electrons to complete their octet.

What is Electronegativity?

Covalent Bonds

Covalent Bonds form when atoms share an electron to gain eight valence electrons (octet rule)

•Mg + 2Cl _______

•H + F ______

•Ca + O ________

Use your periodic table, find each element’s group, write out the Dot Diagram for each reactant, decide if it is ionic or covalent, then write the products.

Now you try!

bellringer!!! you have 5 minutes left!

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