Periodic TableTrends and Similarities

Trends of the Periodic Table:At the conclusion of our time together, you should be able to:

1. Give a trend across and down the Periodic Table for metallic characteristics, reactivity, atomic radius and ion radius, electron affinity, ionization energy, electronegativity, density, melting point and boiling point

2. Pick the element with the higher trend above from a list of several elements

Trends In The Periodic Table:

Ionization EnergyAtomic Radius

Electron AffinityElectronegativity, Etc.

Periodic Trends

Try to determine the trends by looking at the handouts provided.

Metallic Characteristic Trends

Top to Bottom Left to Right

Increases Decreases

ConductivityShininess

MalleabilityDuctility

Reactivity Of MetalsReactivity Of Metals

more reactive

mo

re r

eact

ive

Reactivity Trends

Top to Bottom Left to Right

Increases with MetalsDecreases

with Nonmetals

Decreases with MetalsIncreases

with Nonmetals

Atomic Radius

½ the distance between the nuclei of two identical atoms that are bonded together.

1. Energy level, n, as they go higher = larger

2. Proton – electron attraction = smaller

Atomic Radius Vs. Atomic Number

H He

Li

Be

B C N O FNe

Na

MgAl Si P S Cl

Ar

K

Ca

0

50

100

150

200

250

0 2 4 6 8 10 12 14 16 18 20

Ato

mic

Rad

ius

(pm

)

Element

Atomic Radius Trends

Periodic Table Trends

Answers

Atomic Radius Trends

Top to Bottom Left to Right

Increases Decreases

Ionic Radius

1. Cations lose electrons, therefore they tend to be

Positive Ions - Metals

2. Anions gain electrons, therefore they tend to be

Negative Ions - Nonmetals

Ionic Radius Trends

Electron – electron repulsion =

Larger

Ionic Radius Trends

Metals Nonmetals

Smaller Larger

Electron Affinity

The energy change that occurs when a neutral atom acquires an electron.

Most electron affinity values are negative. Energy is released from the atom.

Atoms that really want another electron tend to be more negative.

Periodic Table Trends

Answers

Electron Affinity Trends

Top to Bottom Left to Right

Decreases(less

negative)

Increases(more

negative)Noble Gases

= 0

Ionization Energy

The energy required to remove one electron from a neutral atom.

The closer to the nucleus, the harder to pull the electron.

The farther away, more interference from other electrons, therefore, the easier it is to pull the

electron.

Ionization Energy Vs. Atomic Number

H

He

Li

Be

B

C

N O

F

Ne

Na

MgAl

SiP S

Cl

Ar

K

Ca

0

500

1000

1500

2000

2500

0 2 4 6 8 10 12 14 16 18 20

Ioni

zatio

n en

ergy

(kJ

/mol

)

Element

Ionization Energy Trends

Ionization Energy Trends

Top to Bottom Left to Right

Decreases Increases

Electronegativity

A measurement of the ability of an atom in a chemical compound to attract electrons.

Generally,

Ionization energy + Electron Affinity = Electronegativity

Most electronegative element – Fluorine (F) It is assigned the number 4 All other values are based on this value.

Electronegativity Trends

Electronegativity Trends

Top to Bottom Left to Right

Decreases Increases

Density

Mass of a Material

Divided by

Volume of that Material

Density Trends

Density Trends

Top to Bottom Left to Right

IncreaseIncreases

then Decreases

Boiling Point

Temperature at which a system moves from the liquid state to the gaseous state. The external pressure pushing into the liquid is equal to the internal pressure pushing out of the liquid.

Melting Point

The temperature at which a solid becomes a liquid. The external pressure pushing into the solid is equal to the internal pressure pushing out of the solid.

Boiling Point Trends

Boiling/Melting Point Trends

Top to Bottom Left to Right

Increases except

Groups 1, 2, 12, 13, 14

Increases then

Decreases

Trends of the Periodic Table:Let’s see if you can:

1. Give a trend across and down the Periodic Table for metallic characteristics, reactivity, atomic radius and ion radius, electron affinity, ionization energy, electronegativity, density, melting point and boiling point

2. Pick the element with the higher trend above from a list of several elements