Tuesday, July 5, 2011
2SAS #1-12, p. 130
1) Classify each of the following as a chemical or a physical property:
a. copper has a reddish brown color.
b. propane burns readily.
c. CO2 gas extinguishes a candle flame.
d. Honey pours more slowly than does water.
a. Physical property.
b. Chemical property.
c. Chemical property.
d. Physical property.
2) Classify each of the following as a chemical or a physical property:
a. Metal wire can be bent.
b. Ice floats in water.
c. Paper is flammable.
d. Sugar is soluble in water.
a. Physical property.
b. Physical property.
c. Physical property.
d. Chemical property.
3) Classify each of the following as a chemical or a physical change:
a. a candle burns.
b. an opened carbonated beverage fizzes.
c. hair curls as a result of a "perm."
d. as shoes wear out, holes appear in the soles.
a. Chemical change.
b. Physical change.
c. Chemical change.
d. Physical change.
4) Classify each of the following as a chemical or a physical change:
a. a cut apple left out in the air turns brown.
b. flashlight batteries lose their "charge" after extended use.
c. dry cleaning removes oils from clothing.
d. Italian salad dressing separates over time.
a. Chemical change.
b. Chemical change.
c. Physical change.
d. Physical change.
5) For each of your answers in Question 4, give evidence for your classification as a chemical or physical change.
a. The atmospheric gases other gases react with the inner part of the apple and causes it's top layer to decay.
b. The flashlight batteries contain chemicals, and once stored energy is gone, the chemical reaction is reversed to get electricity out of the battery.
c. The oils in the clothing are simply removed from the clothing, but the clothing remains the same.
d. The substances within mixture of salad dressing gradually separate and suspend within the container, a chemical change does not occur.
6)
a. List the steps involved in making chocolate chip cookies from scratch.
b. Classify each step in Question 6a as involving either a chemical change or a physical change.
a. Mix ingredients such as milk, eggs, sugar, flour, and chocolate chips together in a bowl. Then, put the batter on a baking sheet and place it in the oven. When taken out of the oven, allow to cool.
b. A chemical change occurs when all the ingredients are mixed together and heated in the oven. they form cookies, one substance formed after all the ingredients are mixed together and heated. Coming out of the oven and cooling is a physical change, the heat of the cookie changes, not the cookie itself.
7) Classify each property as characteristic of metals or nonmetals:
a. shiny in appearance.
b. does not react with acids.
c. shatters easily.
d. electrically conductive.
a. metals.
b. nonmetals.
c. nonmetals.
d. metals.
8) Classify each of these elements as a metal, a nonmetal, or a metalloid:
a. tungsten
b. antimony
c. krypton
d. sodium
a. metal.
b. metalloid.
c. nonmetal.
d. metal.
9) List the names and symbols of two elements that are metalloids.
1) Silicon: Si
2) Arsenic: As
10) What would you expect to happen if you tapped a sample of each of the following elements with a hammer?
a. iodine.
b. zirconium.
c. phosphorus.
d. nickel.
a. it would shatter (brittle).
b. it would flatten (malleable).
c. it would shatter (brittle.
d. it would flatten (malleable).
11) List two properties that make nonmetals unsuitable for electric wiring.
Nonmetals do not conduct electricity and are not malleable; therefore, nonmetal wiring would be brittle and unable to bend very well and would not even be able transmit electricity!
12) List three properties that make metals suitable for use in coins.
1) Metals are malleable, therefore, they can be engraved with currency symbols and political leaders.
2) Metals are shiny in color and make more attractive coins!
3) Metals aren't easily shattered or broken, for they aren't brittle like nonmetals.
ReplyDeletecheap Ray-Ban sunglasses uk, combining elegant style and cutting-edge technology, a variety of styles of cheap Ray-Ban new-wayfarer, the pointer walks between your exclusive taste style.