THE PERIODIC TABLE

Mr. NelsonChemistry

Periodic Table

Group – Vertical columns on PT Period – Horizontal rows on PT

Main-Group Elements

Groups 1, 2, and 13-18

Main-Group Elements

The chemical properties of the main-group elements depends on their number of valence electrons

Valence electrons are the outermost electrons involved in chemical bonding

Valence Electrons & Chemical Properties Each group of the main-group

elements has the same number of valence electrons

Each element wants to be as stable as possible

All main-group elements want a full shell of electrons, which is 8 valence electrons

Valence Electrons & Chemical Properties Each group forms ions based on

the easiest way to obtain this full shell

Also known as the octet rule

Family Groups

Noble Gases (Group 18) Examples: Ne, Xe Description:

stable, unreactive group of gases

Number of Valence Electrons: 8

Forms NO ions

Family Groups

Halogens (Group 17) Examples: F, Cl Description: Highly reactive group of gases

Number of Valence Electrons: 7

Forms 1- ions

Family Groups

Alkali Metals (Group 1) Examples: Na, K (not H) Description: Highly reactive group of metals

Number of Valence Electrons: 1

Forms 1+ ions

Brainiac Movie

Family Groups

Alkaline-Earth Metals (Group 2) Examples: Be, Mg Description: Slightly less reactive group

than alkali metals Number of Valence Electrons: 2 Forms 2+ ions

Family Groups

Transition Metals (Group 3 – 12) Examples: Fe, Au, Ag Description: Fairly stable group of metals Forms multiple ions

Family Groups

Lanthanides & Actinides Location: Bottom 2 periods of PT Description: Heavy metals, synthetics,

radioactive

States of Matter

Metals and Nonmetals (Staircase)

SECTION NEEDS TO BE REDONE

WITH THE GROUP/PERIOD

TRENDS OUTLINED FIRST!!!!!!!!!!!!!!!!

!!!!!

Periodic Table Trends

Atomic Size Definition: The volume occupied by

the electrons around a nucleus Period Trend

Caused by: Increasing Effective Nuclear Charge

Atomic Size

Effective nuclear charge is the amount of charge felt by outer electrons in an atom

Group trend Caused by: Increasing electron energy

levels

Ionization Energy

Definition: The amount of energy required to remove one electron Period trend

Caused by: Inc. Effective Nuclear Charge

Ionization Energy

Group trend Caused by: Electron shielding Electron shielding occurs when inner

electrons shield outer electrons from the pull of the nucleus

Electron Affinity

Definition: The attraction of an atom for an electron

Period Trend Caused by: Inc. Eff. Nuclear

Charge

Electron Affinity

Group trend Caused by: Inc. electron shielding

Electronegativity

Definition: How much an atom in a chemical bond attracts electrons

Period trend Caused by: Inc. Eff. Nuclear

Charge

Electronegativity

Group trend Caused by: Electron shielding/Inc. electron energy levels

Electron shielding

Electron energy levels

Effective Nuclear Charge

Filling Electron Orbitals

Orbitals are the area in space where electrons are found Each individual orbital holds 2 electrons

There are four main shapes which hold a different number of electrons

Shapes of Orbitals

The four shapes are s, p, d, and f

Shapes of the Orbitals

Each shape holds a different number of orbitals s has 1 orbital, p has 3 orbitals, and d has 5 orbitals

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Energy Levels Each period

is a new energy level Like an

elevator, electrons cannot exist between energy levels!

General Rules

Aufbau Principle – Electrons fill lowest energy level first Analogy: Lazy Tenant Rule

General Rules

Pauli Exclusion Principle – Electrons must have opposite spin (up/down) when in the same orbital

Analogy: Yin and Yang Rule

General Rules

Hund’s Rule – Electrons in equal energy orbits fill orbitals with parallel spin Analogy: Empty Bus Seat Rule

Orbital Notation

Specific order for filling electrons – based on periodic table

Examples Beryllium

Oxygen

Orbital Notation

Examples O2-

Titanium

Electron Configuration

Examples Silicon

Selenium

Manganese

Shorthand Electron Config

Shorter version of writing electron configurations Noble Gas Core

– inner core of electrons not involved in chemical bonding

Shorthand Electron Config