Matter and Minerals

What is Matter?

• Matter – the substance of which any physical

object is composed

States of Matter:

• Solid

• Liquid

• Gas

Controlling factors:

• Temperature

• Pressure

Examples: Gold Mercury Oxygen

solid liquid gas

The stuff that makes up all matter

• The make-up of solid matter on Earth:

Atoms Elements Compounds Minerals Rocks

(smallest) (largest)

• Elements:

– fundamental building blocks

– smallest matter that can’t be broken down

Periodic Table of Elements

The stuff that makes up all matter

• The make-up of solid matter on Earth:

Atoms Elements Compounds Minerals Rocks

(smallest) (largest)

• Atoms:

– the stuff that builds elements

– the smallest particle that uniquely defines an element

Atomic Structure

• Particles that make up an atom:

– Protons: positive (+) charge

– Neutrons: no charge

– Electrons: negative (-) charge

Protons + neutrons define the nucleus of an atom.

Layers of electrons that orbit around the nucleus

are called orbitals or energy-level shells.

Atomic Structure

YES

These are called isotopes.

Example: (Carbon) 12C 13C 14C

Periodic Table of Elements

Atomic Number (# of protons)

Mass number = # protons + # neutrons

Can atoms of the same element have

different mass numbers?

Atomic weight =

# protons + average # neutrons

Atomic Structure

• Atoms of the same element:

• have the same number of protons

(i.e., same atomic number)

• can have different numbers of neutrons

(referred to as isotopes)

• can have different numbers of electrons

• Ion – an atom that has gained or lost an electron

Atomic Structure

Sodium atom

loses an electron(becomes positively

Charged ION)

Chlorine atom

gains an electron(becomes negatively

Charged ION)

An Ion is a particle that is electrically charged (positive or

negative); an atom or molecule or group that has lost or gained

one or more electrons

Atomic Structure

• Types of IONS:

• CATIONS – a loss of electrons, resulting

in a positive (+) charge

• ANIONS – a gain of electrons, resulting

in a negative (-) charge

Examples: Na+ (cation) Cl–

(anion)

NaCl (table salt)chemical compound

Compounds

• Definition:

– A chemical compound consists of elements

that combine in a specific ratio.

Examples: NaCl H2O

• The smallest quantity of a compound is

called a molecule.

• Molecules are held together by chemical

bonding.

Bonding – chemical matrimony

• Ionic bonding:

– orderly arrangement of oppositely charged ions

– bonds are moderately strong (salt dissolves in water)

Bonding – chemical matrimony

• Metallic bonding:

– electrons drift around from atom to atom(e.g., copper, gold, silver)

– good conductors of electrical current

– generally weaker, less common than other bonds

Gold, Au

Bonding – chemical matrimony

• Van der Waals bonding:

– sheets of covalently bonded atoms held together by weak electrostatic forces

– very weak bonds

examples: graphite, mica

Atoms Elements Compounds Minerals Rocks

(smallest) (largest)

The stuff that makes up all matter

• The make-up of solid matter on Earth:

Minerals: the building blocks of rocks

• Definition of a Mineral:

naturally occurring

inorganic

solid

characteristic crystalline structure

definite chemical composition

• Definition of a Rock:

• A solid aggregate (mixture) of minerals

Physical Properties of Minerals

1- Optical Properties

Color

Streak

Luster

Diaphaneity

2- Cohesive Properties

Hardness

Cleavage

Parting

Fracture

Tenacity

3- Sense Properties

Touch

Odour

Teste

4- Specific Gravity 5- Other Properties such as: Magnetism, Electricity,

Radioactivity, Fusibility and Solubility

Mineral characteristics

• Definition of a Mineral:

1. naturally occurring

2. inorganic

3. solid

4. characteristic crystalline structure

5. definite chemical composition

steel plastic sugar table salt mercury ice coal

basalt obsidian mica gold paper chalk coral

no, #1 no, #1 no, #1,2 YES! no, #3 YES! no, #2

no, #5 no, #4 YES! YES! no, #1,2 no, #2 no, #2

Mineral characteristics

• Naturally formed

– No substance created artificially is a mineral.

examples: plastic, steel, sugar, paper

• Inorganic

– Anything formed by a living organism and

containing organic materials is not a mineral.

examples: wood, plants, shells, coal

• Solid

– Liquids and gases are not minerals.

examples: water, petroleum, lava, oxygen

Mineral characteristics

• Characteristic crystalline structure

– must have an ordered arrangement of atoms

– displays repetitive geometric patterns in 3-D

glass not a mineral (no internal crystalline structure)

• Definite chemical composition

– must have consistent chemical formula

examples: gold (Au), quartz (SiO2), orthoclase (KAlSi3O8)

basalt (like many other rocks) contains variable ratios

of different minerals; thus, has no consistent formula

– Only ~30 occur commonly (whew!)

– Why not more?

• Some combinations are chemically impossible

• Relative abundances of elements don’t allow more

How many minerals are there?

• Nearly 4,000 types of minerals

Element abundances in the crust

All others: 1.5%