We will learn to use the periodic table as tool

Like a calculator in math class

Properties of Metals• Good

conductors of heat & electricity—called conductors

• Shiny• Ductile--can be

stretched into thin wires

Properties of Metals

• Malleable--can be pounded into thin sheets

• Corrodes--reacts with oxygen in the air to form new compound

Properties of Non-Metals

• Poor conductors of heat & electricity—called insulators

• Not ductile or malleable

sulfur

Properties of non-metals• Many non-metals

are gases• Solid non-metals

are brittle --means break

easily• Dull

CARBON

Another suffix: -oid

• Suffix -oid means “like” or “resembling”

• Examples:

humanoid

asteroid

Metalloids

• Elements that sometimes behave like metals and sometimes not

• 7 of these

Properties of Metalloids• Can have

properties both metals & non-metals—depending on use

• semi-conductors• Separate metals

and nonmetalsgermanium

germanium

Location of element on periodic table will “tell” us a lot about element

MetalloidsMetalloids

Non-MetalNon-Metal

MetalsMetals

Why are elements #57-102 placed at the bottom of the periodic table?

Reason for separation-

convenienceIf table were put together the periodic table would not fit on a single sheet of paper.

Periodic Table in sections

Periodic Table

• Arranged in several patterns

• We will learn many

Rows

• Horizontal arrangements of elements

• 7

• Called periods

Periods

1

2

3

4

5

7

6

6

7

Columns

• Vertical arrangements of elements

• 18

• Called groups or families

Groups or Families

1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

18

Family Names

a.k.a.

Group Names

Family Names• Group 1—Alkali Metals• Group 2—Alkali Earth Metals• Group 3-12—Transition metals• Group 13—Boron Family• Group 14—Carbon Family• Group 15—Nitrogen Family• Group 16—Oxygen Family• Group 17—Halogen Family• Group 18—Inert Gases or Noble Gases

Family Characteristics

• Group 1—Alkali Metals (pH greater than 7 which means they are bases) Most reactive group

• Group 2—Alkali Earth Metals (pH greater than 7 which means they are bases)

• Group 3-12—transition metals (their electron arrangement can change)

• Group 13—Boron family• Group 14—Carbon family

Family Names

• Group 15—Nitrogen family

• Group 16—Oxygen family

• Group 17—Halogens (produce salt)

• Group 18—Noble gases or inert gases (will NOT react with anything)

Names of the elements at bottom (remember not GROUP)

• Elements 57-70 are Lanthanides

• Elements 89-102 are Actinides

• Elements 57-102 make up the Rare Earth Metals

Reading each block on the periodic table

Cr24

chromium51.996

Chemical symbolor

Element symbol

Chemical nameor

Element name

Average atomic mass

Atomic number

FYI

• #92, U, is last natural element

• Every element after #92, U, is synthetic

Chemical symbols

• 1, 2, or 3 letters

• Used instead of writing chemical name

• Universal

• “Language of Chemistry”

• Style of how letters are written matters

• Size of how letters are written matters

Rules for writing chemical symbols:1)1st letter MUST be written uppercase

2)Any following letter MUST be written lowercase

3)No cursive

What does symbol mean?

• Use symbols instead of words

H means one atom of hydrogen

Rh “ “ “ “ rhodium

Cu “ “ “ “ copper

Ti “ “ “ “ titanium

These have same answer.

• Write something that means “one atom of lithium.”

Li• What is the symbol for lithium?

Li

Question:

• The symbol for thallium is Tl. This is an uppercase t and a lowercase L. How do we know that is an L and not an i?

Answer #1:

• Second letter of every symbol is ALWAYS lowercase. If the second letter were an uppercase I that would be violating symbol writing rule.

• Besides Ti is symbol for titanium. Symbols are NEVER duplicated.

Atomic numbers

• Whole numbers—always!!!

• Never duplicated

• Periodic table is arranged by increasing atomic numbers

Average Atomic mass• Measure of how much matter

there is an atom or subatomic particles (e-, p+, n0)

• So tiny—created new unit--atomic mass measured in atomic mass unit (amu)

• Atomic mass on periodic table are averages*

Average atomic mass

• Usually decimal number

• Can be written in parentheses

--means atomic mass is estimated

• Can be duplicated

Why some atomic masses are estimated?

• Some elements are unstable

• Decompose quickly

• Measuring mass is difficult

• Some elements are synthetic

--means man-made

Question

Answer:

--Atomic mass is usually a decimal number or will be written in parentheses that means the other whole number in the box must be the atomic number

What we know:• What periodic table is• What words on periodic table are• What numbers on periodic table are• What symbols on periodic table are• What classification each element is on periodic table• What some of the properties are for each element• What are the family names

•Now…

Elements within a section have similar atomic structure

Atoms• Smallest particle

of element that has properties of that element

• Made-up of:

electrons

protons

neutrons

• Abbreviations

electron e-

proton p+

neutron n0

Charges of e-, p+, and n0?

• Electrons= negative e-

• Protons=positive p+

• Neutrons=neutral n0

(neutral means no charge)

Where are e-, p+ & n0 located?

• Electrons—outer limits of atom in area called electron cloud

• Protons & neutrons—innermost area of atom called nucleus

• Electron cloud has a negative charge.

• Nucleus has a positive charge.

Charge of every atom

• Neutral

• Why???

• Example: silver 47- (electrons)

47+ (protons) _________

neutral charge

Atoms Review• Electrons

--charge of each 1-

--located: electron cloud• Protons

--charge of each 1+

--located: nucleus • Neutrons

--no charge/neutral

--located: nucleus

FYI: Mass of subatomic particles

• Mass of 1 proton = 1 amu

• Mass of 1 neutron = 1 amu

• Mass of 1 electron = 1/2000 of an amu

--Takes 2000 electrons to = 1 amu--Extremely, extremely, extremely, extremely, extremely, small

Atomic structure• How many protons?

--atomic number

• How many electrons?

--atomic number

Using atomic mass

• Round to a whole number; known as an element’s mass number

• Number of protons and neutrons in nucleus

For example: atomic mass mass #

bromine 79.904 80

Atomic mass—mass number

• Gold has atomic mass of 196.97 amu which rounds to 197

• 197 is number of protons and neutrons in nucleus

• Gold has 79 protons so remaining particles in nucleus are neutrons

• 197 (mass number) – 79 (p+) = 118 (n⁰)

Atomic structure• How many protons?

--atomic number

• How many electrons?

--atomic number

• How many neutrons?

--mass number minus atomic number

--mass number minus protons

Electrons, electrons, electrons

Electrons

• Electrons have negative charge and are found in electron cloud in energy levels

• There are 7 energy levels

• Valence electrons are the electrons that are the farthest from the nucleus—found in outermost energy level---maximum number is 8

• Periodic table will give you this information

Valence Electrons

• An element that has 8 valence electrons is “happy”—will not react

• EXCEPTION: Helium is “happy” with 2 because it has only one energy level and the maximum number of electrons in that energy level is two

Electrons

1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

18

1

2

3

4

5

6

7

6

7

Atomic Structure “Cheats”

• Mass number- average atomic mass rounded to a whole number.

• # p+atomic number• #n⁰ mass number minus p+• #e- same as p+• # Ve- ones place of group

number with the exception of groups 3-12 which can NOT be predicted

• Energy level period #

Periodic Table in orbitss P

D

F

* 1

2

3

4

5

6

7

6

7

1

2

3

4

5

6

7

6

7

Electron Configuration

•1S² # of e- in that orbit

Energy Level Orbit

Electron Configuration of Ga:

1S²2S²2P⁶3S²3P⁶4S²3D¹º4P¹

Constructing atomic models

• Entire model elements 1 – 20

• Model of nucleus for every other element

Step 1—atomic model

• Draw circle (representing nucleus)

Al

Step 2—atomic model

• Write p and n in nucleus

pn

np

Al

Step 3—Insert correct values

np13

14Al

This model shows 13 protons and 14 neutrons.

Step 4—add energy levels*

14 n

p13

Al

*Can be determined by using periodic table.

Circles should beconcentric.

Remember:This circle representsthe nucleus; it is NOTan energy level.

Step 5 – add electrons (proper number & location)

• Each energy level holds a specific number of e-

• P.T. shows you how many• Use P.T. as tool!!! Do not attempt to

memorize a list of numbers!!!!!!!!!!!!!• (Examples given in class)

• 3rd – 7th energy levels more detail later

Step 6—add symbol

13 P14 N

Al