Grade 8 Category 1 Test

1Both gypsum and limestone are found in the quarry. Limestone has about the same hardness as calcite. A mineral’s hardness can be determined from how easily it is scratched by another mineral. In a hardness test, what result will show the difference between gypsum and limestone? F Fluorite scratches limestone and gypsum. G Gypsum scratches talc. H Limestone scratches talc. J Calcite scratches gypsum. Mohs Scale of Mineral Hardness HardnessMineral 1Talc 2Gypsum 3Calcite 4Fluorite 5Apatite 6Orthoclase 7Quartz 8Topaz 9Corundum 10Diamond

chlorophyll 6CO 2 + 6H 2 O + light energy → C 6 H 12 O 6 + 6O 2 2Plants use the sun’s energy to make food through photosynthesis. This chemical process is written as the chemical equation shown above. Which of the following lists the three elements that make up the compounds in this equation? A Chlorophyll, carbon, hydrogen B Carbon, sunlight, oxygen C Carbon, oxygen, hydrogen D Water, oxygen, hydrogen

3One of the reactions involved in obtaining pure copper (Cu) from copper-containing rock is Cu 2 S + O 2 → 2Cu + SO 2 Which of the following best describes the reaction? F Copper atoms are used to produce more copper atoms. G Elements are rearranged into new substances. H Atoms of other elements are turned into copper atoms. J Compounds change phase from liquid to gas.

4How many atoms of oxygen are in one molecule of Mg(ClO) 2 ? F 1 G 2 H 3 J 4

5Which of the following best represents the structure of a lithium (Li) atom? AC BD

6Which letter in this model of a boron atom represents a neutron? F W G X H Y J Z

7According to the periodic table, which of the following best represents a carbon atom? AC BD

8How many electrons does gold (Au) have? F 79 G 118 H 197 J 276

9Which of the following situations contains an example of a chemical reaction? A Ice forming after water is placed in a freezer B Watercolor paint drying on paper C A sugar cube dissolving in a glass of water D A bicycle rusting after it is left in the rain

10Which of these is an example of a chemical reaction? F A pot of water boiling G An iron nail rusting H Corn being ground J Sugar dissolving in tea

Composition of a Few Metal Alloys 11Which of these metal alloys does NOT contain copper? ABrass BBronze CPewter DSteel Name of Alloy Elements in Alloy BrassCopper and zinc BronzeTin and copper PewterLead, antimony, tin, and copper SteelIron, chromium, manganese, and carbon

12Which of the following groups of elements from the periodic table contains only metals? A Group 12 B Group 14 C Group 16 D Group 18

13The table above shows the number of protons in an atom of four different elements. According to the periodic table, which of these elements is a metal? A T B Q C X D Z ElementNumber of Protons T7 Q15 X12 Z17

14The model shows the structural formula for methane. Which of these is the proper chemical formula for methane? F 4CH G CH – 4 H 2CH 2 J CH 4

15A person was driving across a hot desert in a car without air- conditioning. If all other factors were equal, the temperature inside the car would have been lowest if the car was – A white B red C blue D black

16Which of the following has the most food energy (calories) per serving? A Peanuts B Macadamia nuts C Cashews D Pistachios PeanutMacadamia NutCashewPistachio Place of OriginBrazil, PeruAustralia South American Rain Forest Middle East Time and Location First Grown in U.S. Early 1800s Southeastern U.S. Early 1880s Hawaii Imported only Mid-1800s Southern California Type of Soil Needed to Grow Silt, sand, clay Open sand, lava rock, heavy clay SandySandy loam Ideal Soil pH 6.0 – 6.5 (slightly acidic) 5.5 – 6.5 (slightly acidic) 5.5 – 7.0 (acidic to neutral) 7.1 – 7.8 (slightly basic) Ideal Temperature Range (°C) 13 – – 40+5 – 28 Ideal Amount of Water Needed (cm/yr) 30 – 4515 – 3150 – – 45 Number of Calories (28g serving)