Level Three / Area Four / Bonding Review

Chemical Bonding Review

Level Two / Area Four

This review is a simple reminder of key points to study. This is not all you should be looking over as you study.

Introduction to Chemical Bonding

• Most atoms are chemically bonded to other atoms. the three major types of chemical bonding are ionic, covalent, and metallic

• In general, atoms of metals bond ionically with atoms of nonmetals, atoms of metals bond metallically with each other, and atoms of non-metals bond covalently with other non-metals

Multiple Choice

Sodium, Na, and Chlorine, Cl, will form NaCl through which type of bond?

• Ionic

• Covalent

• Metallic

• Hydrogen

Multiple Choice

Hydrogen, H, and Oxygen, O, will form H₂O through which type of bond?

• Ionic

• Covalent

• Metallic

• Hydrogen

Introduction to Chemical Bonding

• Most atoms want 8 valence electrons; Octet Rule

• Metals will lose electrons to reach their octet; positive cations

• Nonmetals will gain electrons to reach their octet; negative anions

Multiple Select

Which of the following elements will for cations? Choose all that apply.

• Hydrogen, H

• Oxygen, O

• Magnesium, Mg

• Nitrogen, N

• Sodium, Na

Multiple Choice

How many valence electrons does Oxygen, O, have?

• 7

• 6

• 5

• 4

• 3

Introduction to Chemical Bonding

• Covalent molecules can share electrons equally; nonpolar covalent

• Covalent molecules can share electrons unequally; polar covalent

• Use electronegative difference to determine polarity; <0.3=nonpolar; 0.3-1.7=polar; >1.7=ionic

Multiple Choice

Carbon has an electronegativity value of 2.5 and hydrogen has an electronegativity value of 2.1. Is the bond between Carbon and Hydrogen polar covalent, nonpolar covalent, or ionic?

• Polar Covalent

• Nonpolar Covalent

• Ionic

Covalent Bonding

• Atoms in molecules are joined by covalent bonds. In a covalent bone, two atoms share one or more pairs of electrons.

• Bonding within molecules and ions can be indicated by Lewis structure. Bonds form can be single, double, or triple. Lone pair are represented around the atoms so that the octet rule is met.

• Review how to draw Lewis structures for simple molecules

Multiple Choice

How many double bonds are found in one molecule of water, H₂O?

• 0

• 1

• 2

• 3

Covalent Bonding

• A molecule is a neutral group of atoms covalently bonded

• A chemical compound whose simplest units are molecules is called a molecular compound

• A molecular formula shows the types and numbers of atoms in a single molecule

Ionic Bonding

• An ionic compound is a 3D network of positive and negative ions mutually attracted to one another

• Ionic compounds tend to be harder, more brittle, and have a higher melting point than covalent molecules

Metallic Bonding

• The "sea of electrons" formed in metallic bonding gives metals their properties of high electrical and thermal conductivity, malleability, ductility and luster

Molecular Geometry

• VSEPR theory is used to predict the shapes of molecules based on the fact that electron pairs strongly repel each other

• Three basic shapes are linear (180^o), trigonal planar (120^o), and tetrahedral (109^o)

• Shapes are based on the number of bonded atoms and the number of lone pair around the central atom

• Use the Lewis structure to find the basic molecular shape

Multiple Choice

What is the molecular geometry of a molecule of methane, CH₄?

• Linear

• Bent

• Tetrahedral

• Trigonal Pyramidal