I. Bonding A.Compounds consist of atoms of two or more elements that are joined by chemical bonds B. Types of Bonds 1. A covalent bond is formed when two atoms share electrons.

Chapter 2

2. An ionic bond is formed when one atom gives up an electron to another. The positive ion is then attracted to a negative ion to form the ionic bond.

Remember….. Chemical Reaction 1. reactant + reactant  products before changeafter change

Bell work Explain how a covalent bond is formed and then explain how an ionic bond is formed.

B. Law of Conservation of Mass MASS IS NEVER CREATED OR DESTROYED! 1.Balancing chemical equations helps the # of reactant atoms = # of product atoms. (Reactions keep all the atoms and rearrange them!)

How do you count atoms? CO₂ = 1 carbon and 2 oxygen atoms 2CO ₂ = 2 Carbon and 4 oxygen atoms Ca(OH) ₂= I calcium, two oxygen, and two hydrogen atoms 2Ca(OH) ₂= 2 calcium, 4 oxygen, and 4 hydrogen atoms

How about this hard one! 3 Al ₂(CO₃) ₃ – How many Aluminum? 3 x 2 = 6 aluminum atoms -How many carbon atoms 3 x1 x 3 = 9 carbon atoms -How many oxygen atoms? 3 x3 x3 = 27 oxygen atoms

Now that you can count the atoms are they even on both sides of the reaction? _____ H₂ +_____ O ₂  _____ H ₂O

b. 3O ₂  ___O₃

c. ____ NO(g)  ____ N₂O(g) + ____NO ₂

K+

NO -3

A carbon gives away an electron

Oxygen gains an electron

O-2 gains two electrons