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, and electronegativity.

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 charts on p. 11.

Atomic Radius

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

Atomic Radius Trends

Atomic Radius Trend Explanation

.

1. Electron-electron repulsion makes radius larger, very weak interactions.

2. Proton – electron attraction = smaller atom

3. Energy level, n (distance from the nucleus), as they go higher = larger atom

Atomic Radius Trends

Top to Bottom Left to Right

Increases(larger size

atom)

Decreases(smaller size

atom)

Electron Affinity

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

Energy is released from the atom.

Atoms that really want another electron tend to release more energy.

Electron Affinity Trends

Top to Bottom Left to Right

Decreases(less energy

released)

Increases(more energy

released)Noble Gases

= 0

Ionization Energy

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

Ionization Energy Trends

Ionization Energy Trend Explanation

The closer to the nucleus (smaller atomic radius), the harder to take an electron away.

The farther away from the nucleus (larger atomic radius), the easier it is to take an electron away.

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.

(how strongly an atom holds onto its own electrons and how strongly it needs another electron)

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

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

Ionic Radius Trends

Cations-lost

electron(s)(Metals)

Anions -gained

electron(s)(Nonmetals)

Smaller(compared to original atom)

Larger(compared to original atom)