UNIT: Matter

Objectives: Lesson 2 of 4• You will learn what the periodic table is and how it is arranged and

organized• To know the difference between groups and periods in the

periodic table• To understand the reactivity and properties of the different

groups on the periodic table• To become familiar with the 7 naturally occurring diatomic

molecules

TOPIC: Periodic Table of Elements

QuickwriteAnswer one of the questions below 1-2 sentences:• What are some elements on the periodic table you’re familiar

with?• Why do you think the periodic table is organized the way it is????• How do you think the elements vary or change throughout the

periodic table??• What do know about metals??? If you can, try listing some

physical properties of metals

Periodic Table• In every chemistry room,

you can expect to see a periodic table

• The periodic table is made up of atomic symbols for each element

• The atomic symbol for hydrogen is H, the atomic symbol for Carbon is C

• The periodic table is listed in order of increasing atomic number

• It is also arranged in vertical columns and horizontal rows

Periodic Table• Mendeleev, a Russian

scientist, arranged the elements by atomic number in 1869

• He arranged it this way because of similarities in the chemical properties

• For example, consider fluorine, chlorine, bromine, and Iodine

• Because these elements have a similar electron arrangement, they react and behave in a very similar fashion

What is the Periodic Table?• A table that shows

the names and atomic symbols of elements and is organized by increasing atomic number

• Example: atomic symbol for the element Hydrogen is H

Groups• Elements with similar chemical

Properties that lie in the same vertical column are called groups

• Groups are often referred to by the number over the column

• Fluorine, Chlorine, Bromine and Iodine make up group 17

17

Groups vs. Periods1

6

2

1094 53

13

7 128 11

18

14 1615

17Groups are often referred to by

the number over the columnThere are 18 Groups in the periodic table

Groups vs. Periods1

6

2

45

3

7

The Periodic Table is also organized in horizontal rows called Periods

There are 7 periodsIn the periodic table

What is the difference between Groups and Periods?

• Groups are vertical columns in the periodic table that contain elements with similar chemical properties; 18 groups exist

• Periods are horizontal rows in the periodic table, 7 periods exist

Period

Group

Alkali Metals

In group 1 we have The Alkali Metals

• Group 1 Alkali metals are elements such as Lithium (Li), Sodium(Na), and Potassium (K)

• These metals share similar chemical properties with each other

• They are also very reactive and almost always combine and bond with other elements (Ex. NaCl)

Alkaline Earth Metals

In group 2 we have the Alkaline Earth Metals

• Group 2 Alkaline earth metals include elements such as Beryllium, Magnesium, and Calcium

• These metals share similar chemical properties

Halogens

In group 17 we have the Halogens

• Group 17 Halogens include elements such as Fluorine, Chlorine and Bromine

• Many of these elements are gases or liquids at room temperatures

• Once again, these elements have similar chemical properties

In group 18 we have the Noble Gases

Noble Gases• Group 18 Noble Gases include elements

such as Helium, Neon, and Argon• As their name implies, these elements are

gases at room temperature• Noble gases do not react with other

elements• For example, Helium is always pure helium

atoms

Transition Metals

In groups 3-12, we have the Transition Metals

• Transition metals include many of the elements we are familiar with such as Nickel, Iron, Copper, Gold and Silver

What are the different types of groups?

• Group 1 = Alkali Metals, Example: Sodium (Na), these metals are extremely reactive

• Group 2 = Alkaline Earth Metals, Example: Magnesium (Mg)• Groups 3-12 =Transition Metals, Example: Iron (Fe)• Group 17 = Halogens, Example: Chlorine (Cl)• Group 18 = Noble Gases, Example: Argon (Ar), these gases

are non-reactive or inert and exist in nature as single atoms

• The periodic table is also classified into 3 basic different types of substances:-Metals -Semimetals-Nonmetals

Metals, Semimetals, & Nonmetals

Metals

Nonm

etal

s

Semimetals

• Most of the periodic table is made up of metals• Metals Conduct Electricity• They are Malleable (hammered and flattened), Ductile

(stretched and pulled into wires) and Lustrous (shiny)

Metals

What are Metals?• Most of the periodic table

is made up of metals• Metals conduct electricity,

they are malleable (can be

flattened), ductile (can be

stretched), and lustrous (shiny)

• Ex: Iron (Fe) and Nickel (Ni)

• Please draw:

Semimetals• The elements that divide the Metals

and Nonmetals are semimetals• These elements are also called

Metalloids• They have properties of both Metals

and Nonmetals• Examples of Silicon (used in

computers), and germanium and arsenic

What are Semimetals?• Diagonal band of Elements that separate metals and

nonmetals and have properties of both metals and nonmetals

• Ex: Silicon (Si) and Arsenic (As)

• Please Draw:

• Nonmetals are just like they sound: elements that lack properties of metals

• Nonmetals do not conduct electricity & they are brittle and dull in color

• They also show much more variation than metals do

• Examples would include the oxygen (gas), chlorine (gas), bromine (liquid), sulfur (solid), and carbon (solid)

Nonmetals

What are Nonmetals?• Elements on the right

side of the periodic table that do not have properties of metals

• Nonmetals are brittle, do not conduct electricity, dull in color (not shiny)

• Example: Sulfur (S), Carbon (C)

• Please Draw:

Natural States of the Elements• Elements on the periodic table are different in

how they behave and react with other elements• Some elements such as sodium are very reactive

and readily bond with other elements• Other elements like gold, platinum and Helium

are non-reactive or inert, and do not like to bond with other elements

• It is these chemical properties that make metals like gold and platinum highly valuable and sought after

Noble Gases

= He

• If you remember, noble gases, such as helium, neon and argon are non-reactive and exist in nature as single atoms

• We say these noble gases are monoatomic, or individual lone atoms that are not bonded to any other element

• For example, consider a party balloon filled with Helium (He)

• The balloon is filled with single, lone Helium atoms

Diatomic Molecules• Some elements are found in their

natural state as diatomic molecules • A diatomic molecule is a molecule

made up of 2 atoms bonded together

• For example consider a balloon filled with air

• Air is a mixture of 79 % N2 gas and 20% O2 gas and 1% Argon gas

• N2 and O2 molecules exist in nature as diatomic molecules

• Notice, Argon (Ar), is a monoatomic single atom

= O2

= N2

= Ar

Other Diatomic Molecules at Room Temperature

= Gases: H2 ,O2 , N2 , F2 & Cl2

= Liquids: Br2

= Solid: I2

What are the 7 naturally occurring diatomic molecules?

• A molecule that exists as two atoms in its natural state

• Examples are: H2 ,O2 ,

N2 , F2 , Cl2 , (Gases) Br2

(Liquid) and I2 (Solid)

= Gases: H2 ,O2 , N2 , F2 & Cl2

= Liquids: Br2

= Solid: I2

Summarize:(you can always write you own)

• Compare and contrast Periods and Groups:• In which group can each of the following be found:

– Transition metals– Halogens– Alkali Earth Metals– Noble Gases– Alkali Metals

• Compare and contrast the reactivity of alkali metals and the noble gases; which group is more reactive? Which group is less reactive (inert)?

• Explain the difference between diatomic molecules and monoatomic atoms:• How many diatomic molecules exist in nature?• Describe the physical properties for each of the following:

– Nonmetals– Metals– Semimetals