Earth Science Midterm Review Part 2

Which mineral property is illustrated by the peeling of muscovite mica into thin, flat sheets?

• luster
• streak
• hardness
• cleavage

Which mineral has the greatest density?

• A
• B
• C
• D

A mineral’s crystal shape and cleavage are a direct result of the mineral’s

• hardness
• abundance in nature
• arrangement of atoms
• exposure to the hydrosphere and atmosphere

The accompanying photograph shows actual crystal sizes in a light-colored igneous rock that contains several minerals, including potassium feldspar, quartz, and biotite mica.
This rock can be identified as

• granite
• gabbro
• basalt
• rhyolite

Most rocks that form from fragmental rock particles are classified as

• extrusive igneous
• intrusive igneous
• clastic sedimentary
• chemical sedimentary

Which igneous rock has a vesicular texture and a felsic composition?

• pumice
• basalt
• granite
• scoria

Which mineral will scratch fluorite, galena, and pyroxene?

• graphite
• calcite
• olivine
• dolomite

Which two elements are most useful for the radioactive dating of recent organic remains?

• C¹⁴ and N¹⁴
• K⁴⁰ and Ca⁴⁰
• U²³⁸ and Pb²⁰⁶
• Rb⁸⁷ and SR⁸⁷

A bone sample contains only ¹∕₄ of its original radioactive C¹⁴ content. How old is the bone sample?

• 1 C¹⁴ half-life
• 2 C¹⁴ half-lives
• 4 C¹⁴ half-lives
• 8 C¹⁴ half-lives

A sample of wood found in an ancient tomb contains 25% of its original carbon-14. The age of this wood sample is approximately

• 2,800 years
• 5,700 years
• 11,400 years
• 17,100 years