Types of Matter Key Idea #6

Elements and compounds are both made of atoms and can be identified by a unique set of physical and chemical properties.

Elements are chemical substances that make up all

other substances. are made up of only one kind of atom. can’t be broken down into other substances

by any physical or chemical means. are organized on the Periodic Table in

families.

Examples of Common Elements: Copper Helium Aluminum

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Atoms

are the smallest particle that makes up an element.

have a core called a nucleus. are so small, models are used to understand

them.

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Atoms are made up of protons and neutrons - found in the nucleus of an

atom. electrons - found in a cloud around the nucleus.

Protons: positive (+) charge Neutrons: neutral ( ) charge Electrons: negative (-) charge

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Atomic Number

Atomic Number a unique property that identifies an

element tells how many protons are in an

element’s atoms also tells the number of electrons

that surround the nucleus The number of electrons is always

equal to the number of protons

Atomic Mass The average mass of one atom of

an element. Measured in atomic mass units

(amu’s) http://salksperiodictable.wikispaces.com/file/view/Copper.001.png/

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Elements are different from each other because of the number of protons, neutrons, and electrons their atoms contain.

Element Name and

atomic #

# of proton

s

# of neutron

s

# of electron

s

AverageAtomic

Mass

Atomic WeightAverage mass rounded to the nearest tenth

Atomic Mass #

Total # of protons and neutrons

Hydrogen1

1 0 1 1.00794 1.0 1.0

Elements are different from each other because of the number of protons, neutrons, and electrons their atoms contain.

Element Name and

atomic #

# of proton

s

# of neutron

s

# of electron

s

AverageAtomic

Mass

Atomic WeightAverage mass rounded to the nearest tenth

Atomic Mass #

Total # of protons and neutrons

Hydrogen1

1 0 1 1.00794 1.0 1.0

Boron5

5 6 5 10.811 10.8 11.0

Elements are different from each other because of the number of protons, neutrons, and electrons their atoms contain.

Element Name and

atomic #

# of proton

s

# of neutron

s

# of electron

s

AverageAtomic

Mass

Atomic WeightAverage mass rounded to the nearest tenth

Atomic Mass #

Total # of protons and neutrons

Hydrogen1

1 0 1 1.00794 1.0 1.0

Boron5

5 6 5 10.811 10.8 11.0

Carbon6

6 6 6 12.0107 12.0 12.0

Elements are different from each other because of the number of protons, neutrons, and electrons their atoms contain.

Element Name and

atomic #

# of proton

s

# of neutron

s

# of electron

s

AverageAtomic

Mass

Atomic WeightAverage mass rounded to the nearest tenth

Atomic Mass #

Total # of protons and neutrons

Hydrogen1

1 0 1 1.00794 1.0 1.0

Boron5

5 6 5 10.811 10.8 11.0

Carbon6

6 6 6 12.0107 12.0 12.0

Oxygen8

8 8 8 15.9994 16.0 16.0

Elements are different from each other because of the number of protons, neutrons, and electrons their atoms contain.

Element Name and

atomic #

# of proton

s

# of neutron

s

# of electron

s

AverageAtomic

Mass

Atomic WeightAverage mass rounded to the nearest tenth

Atomic Mass #

Total # of protons and neutrons

Hydrogen1

1 0 1 1.00794 1.0 1.0

Boron5

5 6 5 10.811 10.8 11.0

Carbon6

6 6 6 12.0107 12.0 12.0

Oxygen8

8 8 8 15.9994 16.0 16.0

Gold79

79 118 79 196.96655

197.0 197.0

Element Atomic Energy Levels

Level 1: holds up to 2 electrons Level 2: holds up to 8 electrons Level 3: holds up to 18 electrons Level 4: holds up to 32 electrons Level 5: holds up to 32 electrons Level 6: holds up to 18 electrons Level 7: holds up to 2 electrons

In some cases an energy level will not be completely filled before electrons begin to fill the next level.

Francium 

Number of Energy Levels: 7

First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 18 Fourth Energy Level: 32 Fifth Energy Level: 18 Sixth Energy Level: 8 Seventh Energy Level: 1

Potassium

Number of Energy Levels: 4

First Energy Level: 2 Second Energy Level: 8 Third Energy Level: 8 Fourth Energy Level: 1

Note: The third energy level only holds 8 electrons, even though there is room for 18.

The Periodic Table by Energy Levels

http://www.hobart.k12.in.us/ksms/PeriodicTable/energy%20levels.htm

Another name for energy levels is electron shells

The stability of an atom depends on its electron configuration.

The outermost electrons determine the chemical reactivity of the atom and are called valence electrons.

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Model of a Silicon Atom

Valence Electrons When A groups are numbered from

1 through 8, the number matches the number of Valence electrons.

A valence electron is the highest occupied energy level.

Elements have similar properties because they have the same number of valence electrons.

Sodium metal + Chlorine gas = Table Salt

Na + Cl = NaCl (table salt)

When metals and nonmetals react, valence electrons move from the metal atoms to the nonmetal atoms.

Elements on the periodic chart are represented bysymbols and organized by similar properties into groupscalled families.

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Calendars are organized into Days Weeks Months

Elements are organized into

Groups (families) vertical columns

similar to the days of the week on a calendar elements in a group

have similar properties have the same number of valence electrons

Periods horizontal rows

similar to the weeks on a calendar elements in a period

don’t have similar properties are arranged by increasing atomic number have the same number of electron

containing energy levels