1. Elements, Minerals, Rocks, Soil, Agriculture
Unit 3: Geosphere Part 2
Elements, Minerals, Rocks, Soil, Agriculture

2. What are Atoms?
Are made up of chemical elements. Each element has nearly identical atoms. Atoms have three different particles: - protons (+) located in center of atom -electrons (-) located around center of atom -neutrons (0) located in center of atom

3. What is an Element? Elements have the same # of protons and electrons
Number of protons = number of electrons
Isotopes of an element have the same number of protons and electrons, but they have a different number of neutrons.
Many isotopes are radioactive and emit energy and particles.

4. What do Atoms look like? Have energy levels, or shells:
The shells surround the nucleus (center of atom)
Contains electrons- negatively charged particles

5. Why do Atoms form bonds?
When an atom’s does not contain a full outer shell, it is likely to form a chemical bond with one or more atoms.
A compound: consist of two or more elements that are chemically combined in specific proportions.

6. Types of Chemical Bonds
1. Ionic bonds: form between metal and nonmetal
2. Covalent bonds: form between two non-metals.
3. Metallic bonds: form between two metals.

7. the Periodic Table

8. Practice: Is it a metal, non-metal, metalloid? Na N Metal Li H

9. What is a mixture?
Mixture is any combination of two or more substance that are not chemically combined.
Examples of mixtures:
Salt & pepper
_______________________
Sweet tea

10. Organic Vs. Inorganic Organic: Made of Carbon and hydrogen
Normally living organisms or products of living organisms
Inorganic: Made of everything else
Normally non-living or man made

11. Minerals
Mineral: a naturally occurring, inorganic crystalline material with a unique chemical composition.

12. Minerals Characteristics:
Naturally formed- it forms in nature on its own
Orderly crystalline structure
Solid (cannot be liquid or gas)
Has to have a definite chemical composition
Has to have a characteristic crystalline structure

13. What makes a Mineral different?
Mineral characteristics are determined by the arrangement of atoms
Diamond & Graphite have the same chemical composition, but a different atom arrangement.

14. What makes a Minerals different?

15. Examples of Minerals:
Glass- can be naturally formed (volcanic glass is called obsidian)
Ice- is naturally formed, is a solid, has definite chemical composition
Halite (salt)- naturally formed, is solid, has definite crystalline structure.

16. Characteristics of Minerals
Color
Streak
Luster
Crystal form
Hardness
Cleavage
Fracture
Density

17. Characteristic of Minerals- Color
Small amounts of different elements can give the same mineral different colors.

18. Characteristic of Minerals- Color
Is a poor mineral indicator
Minerals can be multiple colors
Many minerals are the same color
Quartz

19. Characteristic of Minerals- Streak
Streak: is the color of a mineral in its powdered form.
More reliable than color

20. Characteristic of Minerals- Luster
Luster: is used to describe how light is reflected from the surface of a mineral.

21. Characteristic of Minerals- Luster
Non-metallic
Looks waxy, greasy or brilliant
Leaves white or no streak on a black streak plate
Metallic
Looks like metal
Leaves a dark streak (black, grey, green, or brown) on a white streak plate

22. Characteristic of Minerals- Crystal Form
Crystal form: is the visible expression of a mineral’s internal arrangement of atoms.

23. Characteristic of Minerals- Hardness
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)

24. Characteristic of Minerals- Cleavage
Cleavage: is the tendency of a mineral to cleave, or break, along flat, even surfaces.
At least one distinct flat side when broken

25. Characteristic of Minerals- Fracture
Minerals that do not show cleavage when broken are said to fracture.
Fracture: the uneven breakage of a mineral

26. Characteristic of Minerals- Density
Density: is a property of all matter that is the ratio of an object’s mass to its volume.

27. Important All minerals are rocks!!!
Not all rocks are minerals nor are they composed of minerals!!!
Example: Coal is a rock and it is organic

28. What is a Rock?
Rocks are any solid mass of mineral or mineral-like matter occurring naturally as part of our planet.
Types of Rocks
Igneous
Metamorphic
Sedimentary

29. What is an igneous Rock? Igneous rocks
Created from cooling of melted rock called magma
As the magma cools it crystallizes

30. Igneous Rocks-Characteristics
Most igneous rocks are very hard
Made of crystals
Layering is not common in igneous rocks

31. Intrusive vs. Extrusive Igneous Rocks
Intrusive igneous rocks from when magma cools slowly under the Earth’s surface.
Large crystals
Extrusive igneous rocks from when the magma cools quickly on the Earth’s surface.
Very small crystals

32. What is a metamorphic rock?
Formed when buried rock is changed under high temperature and pressure
Rock doesn’t melt. Instead, new minerals grow and the rock remains solid.
Gneiss

33. Metamorphic Rocks – Characteristics
Layering is common in metamorphic rocks
Different layers are made up of different minerals
Often made of plates and flaky layers

34. Foliated vs. Nonfoliated Metamorphic rocks
Foliated metamorphic rocks has a banded or layered appearance
Nonfoliated metamorphic rocks does not have a banded texture