Chem-To-Go Lesson 10Unit 3

ANATOMY OF THE PERIODIC

TABLE

You might want to have a periodic table handy during the video!

Dmitri Mendeleev“Father of the Periodic Table”

Henry Moseley

QUICK HISTORY

Arranged the elements in order of increasing atomic mass

Arranged the elements in order of increasing atomic number

Periodic Law - The periodic law states that certain chemical and physical properties repeat themselves every eight elements when the elements are arranged in order of increasing atomic number.

PERIODIC LAW

Periods = rows

Colu

mn

s =

g

rou

ps

MAJOR CLASSIFICATIONS

• Metals• Nonmet

als• Metalloi

ds

Metals• Typically solid at

room temperature

• Conduct electricity and heat

• Shiny

• Malleable

• Ductile

• Lose electrons to be stable

Nonmetals• Diverse in room

temperature state of matter

• Non-conductors

• Brittle

• Non-lustrous

• Gain electrons to become stable

PROPERTIES

SIX IMPORTANT GROUPS

TWO IMPORTANT PATTERNSNumber of Valence Electrons = Column Number

TWO IMPORTANT PATTERNSCommon Charge of the Ion Pattern

Chem-To-Go Lesson 11Unit 3

ATOMIC RADIUS & IONIC RADIUS

TRENDSTrend = a repeating pattern

Periodic Trend = a repeating pattern on the periodic table

ATOMIC RADIUSDefinition: ½ the distance between the nuclei of two identical touching atoms

ATOMIC RADIUSPeriod trend: [row pattern]; atomic radius DECREASES from left to right across a row Group trend: [column pattern]; atomic radius DECREASES from bottom to top of a column

WHY?

•Radius decreases across a period because the nucleus is gaining more protons to become larger and more strongly positive. The electron cloud is drawn in by forces of attraction.

• Radius decreases up a group because there are fewer energy levels at the top of the periodic table.

PERIOD TREND

GR

OU

P T

REN

D

ATOMIC RADIUSMemory

Tool

SAMPLE MULTIPLE CHOICE:

1. Which of the following atoms will has the smallest radius?

a. Tin b. Strontium c. Selenium d. Arsenic

• Use a periodic table!• Find all of the elements.• Apply the trend.

ATOMIC RADIUSMemory

Tool

SAMPLE MULTIPLE CHOICE:

2. Which of the following atoms will has a larger radius than calcium?

a.Aluminum b. Copper c. Potassium d. None

• Use a periodic table!• Find all of the elements.• Apply the trend.

Cation= Positively charged ion (neutral atom has lost one or more electrons)

Anion= Negatively charged ion (neutral atom has gained one or more electrons)

IONS

IONIC RADIUSDefinition: size of the ion; usually compared to the size of its neutral atom

CATION RADIUS

ANION RADIUS

IONIC RADIUS

Cations form by losing electrons. As electrons are

lost, the ion becomes smaller.

Anions form by gaining electrons. As electrons are

gained, the ion becomes larger.

Chem-To-Go Lesson 12Unit 3

IONIZATION ENERGY &

ELECTRONEGATIVITY

1ST IONIZATION ENERGYDefinition: the energy required to remove a first electron from an atom

1ST IONIZATION ENERGY

1ST IONIZATION ENERGY

Period trend: [row pattern]; ionization energy INCREASES from left to right across a row Group trend: [column pattern]; ionization energy INCREASES from bottom to top of a column

WHY?•The energy needed to remove an electron increases as the nucleus becomes more strongly positive and the electrons are drawn in closer to it.

• The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels.

PERIOD TREND

GR

OU

P T

REN

D

1ST IONIZATION ENERGYSHIELDING EFFECT OF CORE ELECTRONS

•The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels.

1ST IONIZATION ENERGYMemory

Tool

SAMPLE MULTIPLE CHOICE:

1. Which of the following atoms will has the smallest ionization energy?

a. Tin b. Strontium c. Selenium d. Arsenic

• Use a periodic table!• Find all of the elements.• Apply the trend.

1ST IONIZATION ENERGYMemory

Tool

SAMPLE MULTIPLE CHOICE:

2. Which of the following atoms has a larger ionization energy than calcium?

a.Aluminum b. Copper c. Potassium d. None

• Use a periodic table!• Find all of the elements.• Apply the trend.

ELECTRONEGATIVITYDefinition: the ability of an atom in a chemical bond to draw the bonding electrons closer to itself

ELECTRONEGATIVITY

Notice that the noble gases are NOT in the image. Since they don’t form bonds, they have no

electronegativity values.

ELECTRONEGATIVITY

Period trend: [row pattern]; electronegativity INCREASES from left to right across a row Group trend: [column pattern]; electronegativity INCREASES from bottom to top of a column

WHY?•The larger and more positive nuclei on the right side of the table are more likely to attract the bonding electrons

• An unshielded nucleus is better at attracting bonding electrons. Fewer energy levels means more electronegativity.

PERIOD TREND

GR

OU

P T

REN

D

ELECTRONEGATIVITYMemory

Tool

SAMPLE MULTIPLE CHOICE:

1. Which of the following atoms will has the highest electronegativity?

a. Tin b. Chlorine c. Neon d. Arsenic

• Use a periodic table!• Find all of the elements.• Apply the trend.

ELECTRONEGATIVITYMemory

Tool

SAMPLE MULTIPLE CHOICE:

2. Which of the following atoms will has a higher electronegativity than P?

a.Oxygen b. Fluorine c. Helium d. None

• Use a periodic table!• Find all of the elements.• Apply the trend.

Group trend: [column pattern]; electron affinity INCREASES from bottom to top of a column

Definition: the amount of energy released when an electron is added to a neutral atom or molecule to form a negative ion.

Period trend: [row pattern]; electron affinity INCREASES from left to right across a row

ELECTRON AFFINITY

PERIOD TREND

ELECTRON AFFINITY

Memory Tool