1. EARTH SCIENCE Prentice Hall EARTH SCIENCE Tarbuck Lutgens 

2. 2 Chapter 2 Elements and Minerals Atmosphere – O 2, N 2 Lithosphere – minerals like SiO 2 (quartz), NaCl (halite or salt) Hydrosphere – H 2 O with Na + and Cl - Biosphere – DNA, proteins, sugars, fats

3. Elements and the Periodic Table 2.1 Matter  Elements are the basic building blocks of minerals.  Over 100 elements are known.

5. Atoms  Smallest particles of matter 2.1 Matter  Have all the characteristics of an element neutrons, which have neutral electrical charges  The nucleus is the central part of an atom and contains protons, which have positive electrical charges

6. Atoms 2.1 Matter  Energy levels, or shells surround the nucleus contain electrons—negatively charged particles Electrons in the outer shell are involved in bonding  The atomic number is the number of protons in the nucleus of an atom.

7. Model of an Atom

8. Isotopes  Many isotopes are radioactive and emit energy and particles.  Isotopes of an element have the same number of protons but varying numbers of neutrons.  Have different mass numbers: the sum of the neutrons plus protons 2.1 Matter  The mass number is the number of neutrons and protons in the nucleus of an atom = the total mass of an atom.

9. Why Atoms Bond A compound consists of two or more elements that are chemically combined in specific proportions.  When an atom’s outermost energy level does not contain the maximum number of electrons, the atom is likely to form a chemical bond with one or more atoms. 2.1 Matter An ion is an atom that gains or loses electrons.

10. Types of Chemical Bonds 1. Ionic bonds form between positive and negative ions. 2.1 Matter 2. Covalent bonds form when atoms share electrons. 3. Metallic bonds form when metal ions share electrons.

11. Definition of a Mineral 2.2 Minerals 1. Naturally occurring 2. Solid substance 3. Orderly crystalline structure 4. Definite chemical composition 5. Generally considered inorganic

12. How Minerals Form 2.2 Minerals 1. Crystallization from magma 2. Precipitation/Evaporation 3. Pressure and temperature 4. Hydrothermal solutions

15. Many minerals start out in liquids that are hot enough to melt rocks. Magma is melted rock inside Earth, a molten mixture of substances that can be hotter than 1,000°C. Magma cools slowly inside Earth, which gives mineral crystals time to grow large enough to be seen clearly mineralsliquidssubstances Granite is a type of rock that forms from magma. It contains the minerals quartz (clear), plagioclase feldspar (shiny white), potassium feldspar (pink), and other minerals.

16. Diamonds form about 160 km below the surface. They are pushed up by rare Kimberlite pipes of gaseous magma.

19. Minerals Formed as a Result of Crystallization of Magma

20. Mineral Groups  Can be classified based on their composition 2.2 Minerals 1. Silicates Silicon and oxygen combine to form a structure called the silicon-oxygen tetrahedron. This silicon-oxygen tetrahedron provides the framework of every silicate mineral. SiO 2, Quartz 96% of minerals in Earth’s crust

21. The Silicon-Oxygen Tetrahedron

22. Silicon-Oxygen Chains, Sheets, and Three-Dimensional Networks

23. Mineral Groups 2.2 Minerals 2. Carbonates Minerals that contain the elements carbon, oxygen, and one or more other metallic elements, fizz when exposed to acids. Calcite CaCO 3 (stalagtite & stalagmites) 3. Oxides Minerals that contain oxygen and one or more other elements, which are usually metals, Magnetite Fe 3 O 4 (magnetic “lodestone”)

24. Mineral Groups 2.2 Minerals 4. Sulfates and Sulfides Minerals that contain the element sulfur, Pyrite (fool’s gold) FeS 2 5. Halides Minerals that contain a halogen ion plus one or more other elements, NaCl (table salt) 6. Native elements Minerals that exist in relatively pure form, gold and silver, Au and Ag

25. Sulfides

26. Native Copper

27. Color 2.3 Properties of Minerals  Small amounts of different elements can give the same mineral different colors.  http://thehappyscientist.com/study- unit/mineral-id-color http://thehappyscientist.com/study- unit/mineral-id-color

28. Streak 2.3 Properties of Minerals  Streak is the color of a mineral in its powdered form.

29. Luster 2.3 Properties of Minerals  Luster is used to describe how light is reflected from the surface of a mineral.

30. Pyrite (Fool’s Gold) Displays Metallic Luster.

31. Crystal Form 2.3 Properties of Minerals  Crystal form is the visible expression of a mineral’s internal arrangement of atoms.

32. Quartz Often Exhibits Good Crystal Form.

33. Hardness 2.3 Properties of Minerals  Hardness is a measure of the resistance of a mineral to being scratched.  Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest).

34. Mohs Scale of Hardness

35. Cleavage 2.3 Properties of Minerals  Cleavage is the tendency of a mineral to cleave, or break, along flat, even surfaces.

36. Mica Has Cleavage in One Direction

37. Fracture 2.3 Properties of Minerals  Minerals that do not show cleavage when broken are said to fracture.  Fracture — the uneven breakage of a mineral

38. Conchoidal Fracture

39. Density 2.3 Properties of Minerals  Density is a property of all matter that is the ratio of an object’s mass to its volume.

40. Distinctive Properties of Minerals 2.3 Properties of Minerals  Some minerals can be recognized by other distinctive properties.

41. Review Question 1 When magnesite (MgCO 3 ) is mixed with hydrochloric acid (HCl), it results in a deterioration of the magnesite and carbon dioxide and water are formed. This reaction results in a fizzing or bubbling as gas is released. Which mineral group does magnesite belong? 1.Silicates 2.Carbonates 3.Oxides 4.Halides