Erth 111 Midterm 1 Exam Questions with
100% Verified Detailed Answers latest
update
Introduction:
This document contains the full set of Midterm 1 exam questions for
ERTH 111 along with 100% verified detailed answers. It covers
foundational topics in geology, including mineralogy, rock types,
the rock cycle, plate tectonics, volcanism, geologic structures,
dating methods, and Earth’s internal processes. The material is
comprehensive and aligns with exam preparation needs, making it
a complete study guide.
Exam Questions and Answers:
Ionic and Covalent Bonds:
Ionic bonds: --- correct answer ---electron stealing +/- attraction:
Moderate bond, moderately hard
Covalent: --- correct answer ---Electron sharing: Strong bond, hard
minerals
,Definition of minerals; mineral groups
Mineral definition: --- correct answer ---Naturally occurring
inorganic solid,
Specific chemical composition
specific internal order
specific physical characteristics (Color, crystal form, cleavage or
fracture, specific gravity, streak)
Mineral groups (12): --- correct answer ---Halides - Cl
Sulfides - S
Sulfates - SO4
Carbonates - CO3
Silicate - SiO4
silicate tetrahedron is SiO4 -4 charge
Silica Oxygen-based minerals --- correct answer ---Quartz, K-
Feldspar, Olivine
Silica tetrahedron - building block of minerals (formula, charge,
shape, why a building block? --- correct answer ---SiO4 -4, 1 silica
ion surrounded by 4 oxygen ions. Shape is like a pyramid.. Silicon
has 14 electrons, of which two orbit the nucleus in the innermost
shell and eight fill the next shell. The four remaining electrons are
, in its outermost "valence" shell leaving it four electrons short.. four
outer electrons are easily borrowed by other elements. Oxygen has
eight electrons, leaving it two short of a full second shell.
Silicate Structures
Minerals of earth's crust
Felsic vs. Mafic vs. Ultramafic silicate minerals
Felsic vs. Mafic. vs. Ultramafic rocks
Felsic Igneous rocks: --- correct answer ---High silica, low Fe and
Mg, low density - Continental crust
Extrusive: Fine-grained: Rhyolite
Intrusive: Coarse-grained: Granite
Mafic igneous rocks: --- correct answer ---Low silica, high Fe and
Mg, low density - Oceanic Crust
Extrusive: fine-grained: basalt
Intrusive: coarse-grained: gabbro
Ultramafic igneous rocks: --- correct answer ---Low silica, high Fe
and Mg, low density - Upper mantle
Intrusive(Plutonic, cooled slowly): Coarse grained: peridotite
100% Verified Detailed Answers latest
update
Introduction:
This document contains the full set of Midterm 1 exam questions for
ERTH 111 along with 100% verified detailed answers. It covers
foundational topics in geology, including mineralogy, rock types,
the rock cycle, plate tectonics, volcanism, geologic structures,
dating methods, and Earth’s internal processes. The material is
comprehensive and aligns with exam preparation needs, making it
a complete study guide.
Exam Questions and Answers:
Ionic and Covalent Bonds:
Ionic bonds: --- correct answer ---electron stealing +/- attraction:
Moderate bond, moderately hard
Covalent: --- correct answer ---Electron sharing: Strong bond, hard
minerals
,Definition of minerals; mineral groups
Mineral definition: --- correct answer ---Naturally occurring
inorganic solid,
Specific chemical composition
specific internal order
specific physical characteristics (Color, crystal form, cleavage or
fracture, specific gravity, streak)
Mineral groups (12): --- correct answer ---Halides - Cl
Sulfides - S
Sulfates - SO4
Carbonates - CO3
Silicate - SiO4
silicate tetrahedron is SiO4 -4 charge
Silica Oxygen-based minerals --- correct answer ---Quartz, K-
Feldspar, Olivine
Silica tetrahedron - building block of minerals (formula, charge,
shape, why a building block? --- correct answer ---SiO4 -4, 1 silica
ion surrounded by 4 oxygen ions. Shape is like a pyramid.. Silicon
has 14 electrons, of which two orbit the nucleus in the innermost
shell and eight fill the next shell. The four remaining electrons are
, in its outermost "valence" shell leaving it four electrons short.. four
outer electrons are easily borrowed by other elements. Oxygen has
eight electrons, leaving it two short of a full second shell.
Silicate Structures
Minerals of earth's crust
Felsic vs. Mafic vs. Ultramafic silicate minerals
Felsic vs. Mafic. vs. Ultramafic rocks
Felsic Igneous rocks: --- correct answer ---High silica, low Fe and
Mg, low density - Continental crust
Extrusive: Fine-grained: Rhyolite
Intrusive: Coarse-grained: Granite
Mafic igneous rocks: --- correct answer ---Low silica, high Fe and
Mg, low density - Oceanic Crust
Extrusive: fine-grained: basalt
Intrusive: coarse-grained: gabbro
Ultramafic igneous rocks: --- correct answer ---Low silica, high Fe
and Mg, low density - Upper mantle
Intrusive(Plutonic, cooled slowly): Coarse grained: peridotite
