The document compares the properties of elements and compounds. It provides examples of the elements sodium and chlorine, which form the compound sodium chloride when combined. Sodium is a soft, silvery metal that reacts easily with water, while chlorine is a greenish-yellow gas that is toxic. When combined, they form table salt, which is a white solid made of cubes. Another example is baking soda, whose scientific name is sodium bicarbonate. It is made up of the elements sodium, hydrogen, carbon, and oxygen. The document instructs the reader to research and chart the physical properties of these elements and compare them to the properties of baking soda.

1. Properties of Compounds1
Name_______________________________
Comparing Properties of Elements &
Compounds
Compounds are combinations of matter. They are two or more elements
whose atoms have chemically combined, or bonded.
When compounds are formed, the properties of the compound are different
from the properties of the elements that make up the compound.
For example:
Sodium [Na] is an element. It is a bright, silvery metal. It is soft and
reacts very easily. It floats on water. It may catch fire when it touches
water.
Photo source: http://resourcescommittee.house.gov
Chlorine [Cl] is an element. It is a greenish-yellow gas. It is an irritant
to the lungs and mucus membranes. High concentrations of chlorine gas
are fatal. Liquid chlorine can burn the skin.
Photo source: http://www.theodoregray.com
When sodium and chlorine combine comically, they form sodium chloride [NaCl], or
everyday table salt. Table salt is a white solid made of tiny crystals that are shaped
like cubes.
Photo source: http://www.lpl.arizona.edu
M. Poarch – 2005
http://science-class.net

2. Properties of Compounds2
Baking Soda [NaHCO3] is another common compound. Another, more scientific name
for baking soda is Sodium Bicarbonate. It is made up of four elements: Sodium [Na],
Hydrogen [H], Carbon [C], and Oxygen [O].
What to do:
Use the following websites to research some of the physical properties of the
elements that make up baking soda. Complete the chart to compare the properties of
each element and the compound.
http://periodic.lanl.gov/elements/11.html
http://www.chemicalelements.com/elements/na.html
http://www.webelements.com/
Property Baking Soda Sodium Hydrogen Carbon Oxygen
Color white
State / phase solid
Melting Point 270°C
Boiling Point N/A
How do the properties of the elements compare to each other? How do they compare
to the compound?
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M. Poarch – 2005
http://science-class.net