Question

1. classify each of the following as mixtures, pure compounds or elements:

a. water (h₂o)
b. air
c. tin (sn)
d. sugar (c₁₂h₂₂o₁₁)
e. sodium hydroxide (naoh)
f. blood
g. salt (nacl)
h. iron (fe)
i. bronze (cu/sn)

1. classify each of the following properties as either a physical or chemical property.

a. hardness of a diamond
b. combustibility of gasoline
c. corrosive character of an acid
d. color of a piece of fabric
e. length of a pipe
f. weight of a rock
g. glue hardens when exposed to air
h. clay vitrifies (hardens) to ceramic when heated

1. is each change a physical or chemical change?

a. melting of glass
b. burning of grass
c. expansion of compressed propane
d. photosynthesis by leaves of a tree
e. gasoline being used by your car
f. color of your favorite shirt fading over time and washing
g. your favorite shirt shrinks if it gets too hot in the drier
h. cutting a piece of wood with a saw

Explanation:

For Question 1:

• Elements are pure substances made of one type of atom.
• Pure compounds are substances made of two+ bonded elements.
• Mixtures are combinations of unbonded substances.

For Question 2:

• Physical properties are observable without changing substance identity.
• Chemical properties describe ability to form new substances.

For Question 3:

• Physical changes don't alter substance chemical identity.
• Chemical changes form new substances.

Answer:

Question 1

a. pure compound
b. mixture
c. element
d. pure compound
e. pure compound
f. mixture
g. pure compound
h. element
i. mixture

Question 2

a. physical property
b. chemical property
c. chemical property
d. physical property
e. physical property
f. physical property
g. chemical property
h. chemical property

Question 3

a. physical change
b. chemical change
c. physical change
d. chemical change
e. chemical change
f. chemical change
g. physical change
h. physical change