3.2. Chemistry of Compounds http://www.ck12.org
Q:Read theFigure3.5 about carbon dioxide (CO 2 ) and carbon monoxide (CO). Both compounds consist of carbon
and oxygen, but in different ratios. How can you tell that carbon dioxide and carbon monoxide are different
compounds?
A:You can tell that they are different compounds from their very different properties. Carbon dioxide is a harmless
gas that living things add to the atmosphere during respiration. Carbon monoxide is a deadly gas that can quickly
kill people if it becomes too concentrated in the air.
FIGURE 3.5
Carbon Dioxide: Every time you exhale,
you release carbon dioxide into the air.
It’s an odorless, colorless gas. Car-
bon dioxide contributes to global climate
change, but it isn’t directly harmful to hu-
man health. Carbon Monoxide: Carbon
monoxide is produced when matter burns.
It’s a colorless, odorless gas that is very
harmful to human health. In fact, it can
kill people in minutes. Because you can’t
see or smell carbon monoxide, it must be
detected with an alarm.Types of Compounds
There are two basic types of compounds that differ in the nature of the bonds that hold their atoms or ions together.
They are covalent and ionic compounds. Both types are described below. You can learn more about the properties
of covalent and ionic compounds at this URL:
http://www.youtube.com/watch?v=bQ6_8iMd8YM
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/79972- Covalent compounds consist of atoms that are held together by covalent bonds. These bonds form between
nonmetals that share valence electrons. Covalent compounds exist as individual molecules. Water is an
example of a covalent compound. - Ionic compounds consist of ions that are held together by ionic bonds. These bonds form when metals transfer
electrons to nonmetals. Ionic compounds exist as a matrix of many ions, called a crystal. Sodium chloride
(table salt) is an example of an ionic compound.