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Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The...

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Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons
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Page 1: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Atoms

Atoms are made up of protons, neutrons and electrons

Atoms are unique to each element.

The outermost electrons are called valence electrons

Page 2: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Label the Atom

Page 3: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

ElectronsValence electrons are important in deciding

which atoms can bond (chemically combine to form a new substance)

All atoms want to have 8 valence electrons. The only exceptions are H and He.

Hydrogen and Helium only want 2 valence electrons.

Page 4: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

CompoundsElements combine with other elements to get

the 2 or 8 valence electrons.

When two elements chemically combine to form something new the result is called a chemical compound.

When a compound is formed people say a bond was formed between the elements.

Page 5: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Compounds

When two or more elements combine or exchange valence electrons they bond or form a molecule

This is a chemical change because a new substance is formed.

You can see compounds form in chemical reactions or changes.

Page 6: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Learning Launch

• Turn in homework to box (purple sheet) AND get out periodic table

• LL 10/11/2013

• Get out notes from yesterday (white sheet)

Find the number of Find the number of Find the number of Protons for… Neutrons for… Electrons for…Xe _______ He _________ O _______K _______ Si _________ Cl _______Fe _______ I __________ B _______Ne _______ Mg ________ Na ______

Page 7: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

So how and why do these electrons move?

1. The nucleus (center) of the atom is surrounded by swirling electrons.

2. The electrons move on invisible rings called energy levels, orbitals or shells.

Page 8: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Lets look Each orbital or energy level canonly hold a certain number ofelectrons…

3. The first energy level around the nucleus can only hold a maximum of 2 electrons…

it is not strong enough to hold anymore…

Page 9: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

4. Which elements on the periodic table only have 1 or 2 total

electrons?Hydrogen and HeliumREMEMBER!!! Atomic number = number of protons = number

of electronsSo.. You look at the top number to find the total

number of electrons in 1 atom of that element… and the answer to our question is…

Page 10: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

They look like this.

Hydrogen (H) Helium (He)

Atomic Number - 1 Atomic number - 2

1 electron 2 electrons

Page 11: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Lets fill in some info

HydrogenAtomic number: __1___

Has __1____ electron and __1____ proton.

In Group/Family number_1__

In Period: __1___

Has ___1___ energy level

HeliumAtomic number: ___2___

Has __2___ electrons and ___2___ protons.

In Group/ Family number __18__

In period _____1___

Has ___1_____ energy level.

Page 12: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

What next…

7. Once the first energy level has two electrons on it, it is full, so if an atom has more than 2 electrons, it needs another energy level…

Lets look at Lithium.Lithium – atomic # 3

Page 13: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

LithiumLithium has an atomic number of..

That means that is has protons and electrons.

Can all of Lithium’s electrons fit on one energy level??

NOOOOO!

Page 14: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Because the first energy level can only hold a max. of 2 electrons…

An atom of Lithium (Li) must have two energy levels to fit all3 electrons.

It looks like this

Page 15: Atoms Atoms are made up of protons, neutrons and electrons Atoms are unique to each element. The outermost electrons are called valence electrons.

Fill in info on Lithium

Atomic number: __3__Has __3____ electrons and __3____ protons.In Group/Family number_1__Has _1____ valence electronIn Period: __2___Has _2___ energy level


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