Periodic TableTrends

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

Atomic Radius

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

1. Electron – electron repulsionMakes radius larger

1. Very weak interactions

Atomic Radius con‘t

2. Proton – electron attraction = Makes radius smallerVery Strong interactions

Proton electron attraction is a million times stronger than electron electron repulsion

Atomic Radius con’t

Down a group/family3. Energy level, n, increases from top to bottom

Radius gets larger by adding large amounts of electrons

Think Bohr model (adding rings)

Atomic Radius Trends

Atomic Radius Trends

Top to Bottom Left to Right

Increases Decreases

Electron Affinity

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

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 Trends

Ionization Energy Trends

Top to Bottom Left to Right

Decreases Increases

Electronegativity

The ability of an atom to attract electrons.

The most electronegative element is F – Fluorine

It is assigned the number 4 and all other values are based on that value.

Electronegativity Trends

Electronegativity Trends

Top to Bottom Left to Right

Decreases Increases

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

More electron – electron repulsion = larger radiusLess electron – electronRepulsion = smaller radius

Ionic Radius Trends

Metals Nonmetals

Smaller Larger

Anion radius is larger compared to the atom

Cation radius is smaller compared to the atom

Metallic Character

1. Low ionization energy2. Low electronegativities3. High luster – shiny4. Good conductor or electricity and heat5. Malleable and ductile

Most metallic element = Francium

Metallic Characteristic Trends

Top to Bottom Left to Right

Increases Decreases

ConductivityShininess

MalleabilityDuctility

Non Metallic Character

1. High ionization energy2. High electronegativities3. Little or no metallic luster 4. Poor electrical and thermal conductors5. Fewer solids

Most nonmetallic element = Fluorine

Metalloid Character

1. Characteristics of both metals and nonmetals

2. Electronegativities between those of metals and nonmetals

3. Ionization energies between those of metals and nonmetals.

4. Boiling pts, Melting pts and Densities vary widely

1. High luster2. Brittle3. Good conductor

Silicone

Reactivity Trendsmetals ….Franciumnonmetals …Fluorine

Top to Bottom Left to Right

Increases with MetalsDecreases

with Nonmetals

Decreases with MetalsIncreases

with Nonmetals

Density

Mass of a Material / 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