ATOMIC STRUCTUREWhat atoms look like

WHAT ARE ATOMS? An atom is the smallest part of matter that can

exist.

Atoms are microscopic particles. That means we can’t see them! You can fit about 500,000 atoms behind a single

strand of human hair

Atoms are always moving.

How small is an atom?

WHAT ARE ATOMS?

Atoms are made up of 3 main parts:ProtonsNeutronsElectrons

STRUCTURE OF THE ATOM

PARTS OF THE ATOMNucleus- the small center of an

atomSo tiny that it is 1/100,000 the size of

the entire atom!Contains most of the atoms mass

Inside the nucleus:Protons- have a positive charge (+)

Atoms are identified by the number of protons in its nucleus

# of protons in an atom = atomic numberNeutrons- have no charge (0)

Protons and neutrons are the same size

PARTS OF THE ATOMOutside of the nucleus are electron clouds (rings around the nucleus) with even smaller particles!Electrons- have a negative charge (-)

Are much smaller than protons and neutrons

There are the same number of protons and electrons in an atom!

PARTICLE SUMMARYParticle Mass? Charge LocationProton A lot Positive

(+)Inside

the nucleus

Neutron A lot (same as protons)

No charge

(0)

Inside the

nucleusElectron A little Negative

(-)Outside

the nucleus

in electron clouds

ELEMENTS Remember: The number of protons in an atom’s

nucleus determines what the atom is… Atoms help create the….

Elements Made up of only 1 kind of atom (pure substance) Atoms in an element all have the same number of protons Atoms in an element all share the same physical and

chemical properties

An atom with 6 protons is a carbon atom- carbon is an element

ELEMENTS There are over 100 different elements in

the world92 of these are found in the earth

Which elements do you know?SilverAluminumGoldCarbonCopperHelium Iron

HOW TO FIND OUT INFORMATION ABOUT AN ELEMENT:Each square on the periodic table includes

lots of information about an element:

HOW TO FIND OUT INFORMATION ABOUT AN ELEMENT

Name: tells us what element it is

Symbol: the 1 or 2 letter abbreviation that represents the elements name Located in the center of the square

Atomic Number: the number of protons in an element Located above the symbol

Atomic Mass: the number of protons + the number of neutrons in an element Located below the symbol Bigger number

HOW TO FIND OUT INFORMATION ABOUT ELEMENTS How do you know how many protons,

electrons and neutrons are in each element?

Number of protons = number of electrons

Number of protons = Atomic Number

Number of electrons = Atomic Number

Number of neutrons = Atomic mass - Atomic Number

YOU TRY!Element:

NitrogenSymbol:

NAtomic Number:

7Atomic Mass:

14Number of Protons:

7Number of Electrons:

7Number of Neutrons:

7

NNitrogen14.0

7

MOLECULES Molecules are formed when 2 or more

atoms join together

Can be the same kind of elementO2 (air)

2 atoms of oxygen

Or they can be different kinds of elementsH2O (water)

2 atoms of hydrogen and 1 atom of oxygen

ATOMS VS MOLECULESAtoms MoleculesSingle (1 type) Couples or groups (more than

1 atom joined together)