Structures and Properties of Matter Review

1. What is the smallest particle of the element iron (Fe) that can still be classified as iron?

• an atom

• an electron

• a molecule

• a compound

Answer explanation

Atoms are the smallest part (unit) of matter that defines the chemical element.

Oxygen and Hydrogen combine to form water. Which of the diagrams below illustrate a water molecule. Additionally, identify water as any of the following that apply: an atom, an element, a molecule, and/or a compound.

• 
• 
• 
• 

Answer explanation

Water (formula: H20) is made up of two hydrogens and one oxygen. Water is both a molecule and a compound.

* All compounds are molecules, but not all molecules are compounds.

Which of the following does not belong:

• Air

• Salt

• Water

• Oxygen

Answer explanation

Air does not belong because it is a mixture. The rest are pure substances (elements and compounds)

* Remember mixtures are physically combined, but pure substances are chemically combined.

4. Part I: Identify the following as either a pure substance (PS) or mixture (M).

* Some of the options may not be on your study guide.

d

e

f

g

h

i

c

b

a

Kool-aid

Oxygen Gas (O2)

Water (H2O)

Blood

a blueberry muffin

Saltwater (NaCl)

an alloy of iron and carbon

Zinc (Zn)

Carbon Dioxide (CO2)