Modern Chemistry Chapter 6

Chapter 6 Section 3: Ionic Bonding and Ionic Compounds

by Abby Fancsali

​Introduction

• ​Ionic Compound: a compound composed of positive and negative charges, where the charges cancel out

  • ​Most are crystalline solids

  • ​Chemical Formula shows the ratios of ions

  • ​Formula Unit: the simplest collection of atoms from which an ionic compound's formula can be established

    • ​NaCl = 1 Na + 1 Cl

​Formation of Ionic Compounds

• ​Consider the electron dot notation for one sodium and one chlorine atom

  • ​alkali earth metals readily lose one electron to form cations, and halogens readily take electrons to form anions

    • ​Na + Cl --> Na⁺ + Cl^-

​Characteristics of Ionic Bonds

• ​Ionic bonds arrange in a Crystal Lattice pattern

  • ​Positive and negative ions move to where they are the most stable

  • ​Arrangements vary with the sizes and charges of the individual ions

• ​Bond strength compared using Lattice energy

  • ​the energy released when one mole of an ionic crysatlline compound is formed from gaseous ions

​Comparing Ionic & Molecular Compounds

• ​Ionic Bonds

  • ​Bonds between atoms are strong

    • ​Forces of attraction are strong

  • ​Higher melting and boiling Points

  • ​Hard but brittle

  • ​Many dissolve in water

  • ​Electrical Conductors

• ​Covalent Bonds

  • ​Bonds between atoms strong

    • ​Forces of attraction are weak

  • ​Lower Melting and Boiling Point

​Polyatomic Ions

• ​Certain atoms bond covalently to form a group of atoms that have both molecular and ionic characteristics

• ​Polyatomic Ions: A charged group of covalently bonded atoms is known as a polyatomic ion

Cha​pter 6 Section 4: Metallic Bonding

1. ​Chemical bonding is different in metals than in ionic molecular, or covalent bonds

   • ​Unique properties of metals

   • Valence electrons in the d-orbitals

     • ​Best conductors of electricity

       • Highly mobile valence electrons

2. ​Metallic Bonding: The chemical bonding that results from the attraction between metal atoms and the surrounding sea of electons

​Properties of Metals

• ​High Luster

• ​Malleable: Able to be hammered down or beaten into sheets

• ​Ductile: Able to be pulled or drawn through a small opening to create a wire

• ​Bond strength varies with the charge of the metal

Multiple Choice

An ionic bond results from the electrical attraction between

• cations and anions

• atoms

• dipoles

• orbitals

Multiple Choice

What is A charged group of covalently bonded atoms?

• A polyatomic ion

• A cation

• An anion

• a crystal ion

Multiple Choice

What is the simplest collection of atoms from which an ionic compound's formula can be established?

• Formula Unit

• Atom Recipe

• Atomic forumula

• Unit atoms

Multiple Choice

What sort of pattern are ionic bonds arranged in

• A diamond crystal

• A crystal Lattice

• a geometric lattice

• a sphere

Multiple Choice

Which of the following is NOT a property of Ionic bonds?

• High luster

• High Melting point

• High Boiling Point

• Strong force of attraction between elements

Multiple Choice

A covalent bond is formed when two atoms

• share only one electron with one another

• share one or more pairs of electrons with each other

• gain electrons

• lose electrons