Minerals

Question 1

Minerals

Answer 1

Naturally occurring, inorganic, crystalline solids with a definite range in chemical composition and physical properties.

Question 2

Minerals Facts

Answer 2

• There are between 2,000 - 3,000 in the Earth’s crust.
• A few are “native elements” – made of only one element, such as sulfur, gold. copper, and graphite (carbon).
• Most are compounds, especially the silicate group (Si, O).
• Other important groups are oxides, carbonates, and sulfides.

Question 3

What is a mineral composed of?

Answer 3

Minerals are composed of atoms of elements bonded together.
Minerals range in composition from pureelementsand simplesaltsto very complexsilicateswith thousands of known forms.

Question 4

The 8 most common elements in earth crust(by mass) are:

Answer 4

46. 6% Oxygen (O)
47. 7% Silicon (Si)
48. 1% Aluminum (Al)
49. 0% Iron (Fe)
50. 6% Calcium (Ca)
51. 8% Sodium (Na)
52. 6% Potassium (K)
53. 1% Magnesium (Mg)

Question 5

Atoms are composed of subatomic particles?

Answer 5

Protons
Neutrons
Electrons

Question 6

Where are Protons and Neutrons located?

Answer 6

Nucleus

Question 7

Where are electrons located?

Answer 7

They are located around the nucleus in electronic clouds.

Question 8

Protons

Answer 8

They are positively charged.

Question 9

Neutrons

Answer 9

They are neutral charged.

Question 10

Electrons

Answer 10

The are negatively charged.

Question 11

1st shell of the atomic structure can hold?

Answer 11

2 electrons Max

Question 12

2nd shell of the atomic structure can hold?

Answer 12

8 electrons Max

Question 13

3rd shell of the atomic structure can hold?

Answer 13

8 electrons Max

Question 14

4th shell of the atomic structure can hold?

Answer 14

14 electrons Max

Question 15

Why do Atoms of Elements form Compounds?

Answer 15

Chemical bondsare formed betweenatomsbecauseelectronsfrom the atoms interact with each other. Elementsare most stable when their outer electron shells are complete. Atoms bond with other atoms to complete their outer electron shells.
We now know that there are two main types of chemical bonding; ionic bonding and covalent bonding.

Question 16

IONIC BONDING

Answer 16

In ionic bonding a metal gives an electron to an atom which needs extra electrons. This causes both atoms to be charged (IONS). One has a positive charge (it has more protons than electrons) and the other a negative charge. This causes an attraction between the atoms. Materials bonded this way are usually brittle with poor electrical conductivity.

Question 17

COVALENT BONDING

Answer 17

Covalent bonding occurs in ceramics, glass, wood and other organic materials. When atoms bond using covalent bonding the atoms share electrons in their outer shell creating full shells for both.
Covalent bonds give a very strong bond. Diamond is a good example of a strong covalent bond and has a high melting point and is very hard.

Question 18

DIAMOND and GRAPHITE

Answer 18

They are identical chemically—both are composed of carbon (C), but physically, they are very different. Minerals which have the same chemistry but different crystal structures are called polymorphs.
Graphite is opaque and metallic- to earthy-looking, while diamonds are transparent and brilliant.
Graphite is very soft and has a hardness of 1 to 2 on Mohs scale. Diamonds are the hardest known natural substance and have a hardness of 10. No other naturally occurring substance has a hardness of 10.

Question 19

What is the reason their is a difference in hardness and other physical properties?

Answer 19

In graphite, the individual carbon atoms link up to form sheets of carbon atoms which are held together by Van der Waal forces.
In diamonds, each carbon atom is strongly bonded to four adjacent carbon atoms located at the apices of a tetrahedron (a three-sided pyramid).

Question 20

Van der Vaals Bond

Answer 20

Van der Vaals bonds are formed from an electrostatic charge in adjacent atoms. It is present between long-chained molecules in polymers bonding the chains together. When stretched the bonds break easily causing the material to deform.

Question 21

Mineral Properties

Answer 21

Color 
Luster 
Habit(Shape)
Cleavage & Fracture 
Streak
Hardness
Special properties( reaction to acid, fluorescence, salty taste, magnetism)

Question 22

Color

Answer 22

results from ability to absorb some wavelengths and reflect others
some minerals have characteristics colors
others vary due to chemical differences or impurities (atoms mixed inside the main elements)

Question 23

Luster

Answer 23

Describes how light reflects off the surface
Main categories are “metallic” and “non-metallic”
Non-metallic includes “dull,” glassy,” waxy,” “pearly.”

Question 24

Mineral Habit (Shape)

Answer 24

Shape a mineral takes if grown unimpeded

External structure due to the internal arrangement of the atoms

Question 25

Cleavage & Fracture

Answer 25

Some minerals split along flat surfaces when struck hard--this is called mineral cleavage Other minerals break unevenly along rough or curved surfaces--this is called fracture

Question 26

Cleavage & Fracture

Answer 26

``` Cubic Octahedral Dodecahedral Rhombohedral Prismatic Basal ```

Question 27

Streak

Answer 27

The powdered form of a mineral

Question 28

Other Properties

Answer 28

``` Specific gravity Reaction to acid Striations Magnetism Fluorescence ```