Warm Up 9/24
Which subatomic particles are most involved in chemical
bonding?
a. Isotopes
c. Protons
b. Neutrons
d. Electrons
2)
If the atomic number of an element is 6 and its mass
number is 14, how many neutrons are contained in the
nucleus?
a. 20
c. 8
b. 6
d. 14
3)
The most abundant element in Earth’s crust (by weight)
is _______________.
a. Iron
c. Oxygen
b. Calcium
d. Silicon
Answers: 1) d. 2) c. 3) c.
1)
Minerals
Chapter 2, Section 2
Minerals


Mineral – naturally occurring, inorganic
solid with an orderly crystalline structure
and a definite chemical composition
Minerals must have the following
characteristics:
1.
Naturally Occurring
2.
Solid Substance
3.
Orderly Crystalline Structure
4.
Definite Chemical Composition
5.
Generally Considered Inorganic
Minerals
How Minerals Form

There are four major processes by
which minerals form: crystallization
from magma, precipitation, changes in
pressure and temperature, and
formation from hydrothermal
solutions.
Crystallization from
Magma

As magma cools, elements combine to
form minerals.
Precipitation


As water evaporates, some of the
dissolved substances can react to form
minerals.
Changes in water temperature may
also cause dissolved substances to
precipitate out of a body of water.
Pressure and
Temperature

Crystals form when existing minerals
are subjected to changes in pressure
and temperature.
Hydrothermal Solutions


A very hot mixture
of water and
dissolved
substances.
Come into contact
with existing
minerals and the
chemical reactions
between them form
new minerals
Concept Check


Describe what happens when a
mineral is subjected to changes in
pressure or temperature.
The mineral often becomes unstable,
and its atoms react to form a new
mineral
Mineral Groups






Common minerals, together with the thousands of
others that form on Earth, can be classified into
groups based on their composition
Silicates – Silicon and oxygen combine to form a
structure called the silicon-oxygen tetrahedron
Carbonates – Minerals that contain the elements
carbon, oxygen, and one or more other metallic
elements
Oxides – Minerals that contain oxygen and one or
more other elements, which are usually metals
Sulfates and Sulfides – Minerals that contain the
element sulfur
Halides – Minerals that contain a halogen ion plus
one or more other elements
Native Elements – Group of minerals that exist in
relatively pure form
Silicates
Common Silicate Minerals
Carbonates
Oxides
Sulfates and Sulfides
Halides
Native Elements
Concept Check


What is the silicon-oxygen tetrahedron, and
in how many ways can it combine?
The silicon-oxygen tetrahedron consists of
one silicon atom and four oxygen atoms and
provides the framework of every silicate
mineral. These tetrahedra can join to form
single chains, double chains, sheets, and
three-dimensional networks. In these
arrangements the corner oxygen atoms are
shared between silicon atoms so the ratio is
not necessarily 1 to 4.
Assignment


Read Chapter 2, Section 2 (pg. 44-49)
Do Section 2.2 Assessment #1-7 (pg. 49)