COMPLETE EARTH SCIENCE STUDY GUIDE (English)

PART 1: ATOMS – THE BASICS

The 3 Subatomic Particles:

· Proton (p): Positive charge (+). Located in the nucleus.

· Neutron (n): No charge (0). Located in the nucleus.

· Electron (e): Negative charge (-). Orbits around the nucleus.

Two types of chemical bonds (how atoms stick together):

· Ionic Bond: One atom transfers electrons to another. (Example: Salt = NaCl).

· Covalent Bond: Atoms share electrons. (Example: Diamond).

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PART 2: MINERALS

The 5 Rules to be a Mineral (Must memorize!):

A mineral must be:

1. Naturally occurring (not made in a factory).

2. Inorganic (not from plants or animals).

3. Solid (not liquid or gas).

4. Definite chemical composition (has a specific formula).

5. Crystalline structure (atoms are arranged in a repeating 3D pattern).

Physical Properties to Identify Minerals (Exam favorites!):

· Hardness: Mohs Scale (1 = Talc, 10 = Diamond). Trick: If it scratches glass, hardness > 5.5.

· Streak: The color of the powder when rubbed on a porcelain plate. More reliable than outside color.

· Cleavage vs. Fracture:

· Cleavage = Breaks along smooth, flat planes. (Example: Mica peels like sheets).

· Fracture = Breaks with rough, irregular surfaces. (Example: Quartz breaks like glass).

· Luster: Metallic (looks like metal) or Non-metallic (glassy, pearly, earthy).

· Specific Gravity (density).

Main Mineral Groups:

· Silicates (Most common! Contain Silicon + Oxygen). Examples: Quartz, Feldspar, Mica.

· Non-silicates: Carbonates (Calcite), Halides (Halite / rock salt).

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PART 3: IGNEOUS ROCKS ("Born from Fire")

Origin: Form from cooling and solidification of magma (inside Earth) or lava (outside Earth).

Cooling Location Texture Crystal Size Examples

Intrusive (inside, slow cooling) Phaneritic (coarse-grained) Large crystals, visible to naked eye Granite

Extrusive (outside, fast cooling) Aphanitic (fine-grained) or Glassy Small or no visible crystals Basalt, Obsidian (volcanic glass), Pumice (full of holes)

Composition (Color and weight):

· Felsic: High in Silica → Light color, low density. (Granite, Rhyolite).

· Mafic: High in Magnesium (Mg) and Iron (Fe) → Dark color, high density. (Gabbro, Basalt).

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PART 4: SEDIMENTARY ROCKS ("Made of Layers")

Origin: Form from compaction and cementation of sediments. The full process is: Weathering → Erosion → Transport → Deposition → Compaction / Cementation (this whole process is called Lithification).

The 3 Types:

1. Detrital / Clastic (pieces of other rocks):

· Classified by grain size:

· Conglomerate (large, rounded pebbles).

· Sandstone (sand-sized grains).

· Shale (tiny clay-sized particles).

2. Chemical (minerals precipitate from water):

· Chemical Limestone (cave stalactites).

· Rock Salt (Halite – from evaporated seawater).

3. Organic / Bioclastic (remains of living things):

· Coal (plant remains).

· Fossiliferous Limestone (shells).

Key Features to Recognize:

· Stratification (horizontal layers).

· Fossils.

· Ripple Marks (wave patterns) or Mud Cracks (from drying out).

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PART 5: METAMORPHIC ROCKS ("Changed by Heat & Pressure")

Origin: Form when any existing rock (igneous, sedimentary, or metamorphic) is changed by high temperature and high pressure, but NOT melted (if it melts, it becomes magma again).

Two Types of Metamorphism:

· Contact Metamorphism: Changed by heat from nearby magma.

· Regional Metamorphism: Changed by both pressure and heat over large areas (like mountain building).

Classification (The big difference!):

Type Texture What it looks like Examples

Foliated Banded or layered Minerals align in sheets due to pressure. Splits into layers. Slate → Phyllite → Schist → Gneiss (increasing pressure).

Non-foliated Massive, granular No bands. Uniform texture. Marble (from Limestone), Quartzite (from Sandstone).

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PART 6: THE ROCK CYCLE (Connects Everything!)

Memorize this flow:

1. Magma (cools) → Igneous Rock.

2. Igneous Rock (weathering & erosion) → Sediments.

3. Sediments (compaction & cementation = Lithification) → Sedimentary Rock.

4. Igneous or Sedimentary rock (heat & pressure, no melting) → Metamorphic Rock.

5. Any rock (extreme heat / melting) → back to Magma.

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🧮 PART 7: THE ATOMIC MATH (at#, atm, atch) & RADIATION (Alpha, Beta, Gamma)

This is the part your teacher drew on the board. It is just simple math!

The 3 Formulas (Write these on your notes!):

Symbol Name Formula (Just plug in the numbers!)

at# Atomic Number = Number of Protons (p) (That's it. Just count the protons).

atm Atomic Mass = Protons (p) + Neutrons (n) (Electrons are too tiny to count for mass).

atch Atomic Charge = Protons (p) - Electrons (e) (If equal → 0. If p>e → positive. If e>p → negative).

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✏ How your teacher asks this (Step-by-Step Example):

Question: An atom has 9 protons, 10 neutrons, and 9 electrons. Find its at#, atm, and atch.

· at# = p = 9

· atm = p + n = 9 + 10 = 19

· atch = p - e = 9 - 9 = 0 (Neutral)

· Answer: at#=9, atm=19, atch=0.

Question 2 (Charged atom): An atom has 12 protons, 12 neutrons, and 10 electrons.

· at# = p = 12

· atm = 12 + 12 = 24

· atch = 12 - 10 = +2 (Positive!)

· Answer: at#=12, atm=24, atch=+2.

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⚛ What Alpha, Beta, and Gamma do to Protons (p), Neutrons (n), and Electrons (e):

Radiation What leaves the atom Change to p Change to n Change to e

Alpha (α) A helium particle (2p + 2n) - 2 - 2 - 2

Beta (β) A fast electron (a neutron turns into a proton and shoots it out) + 1 - 1 - 1

Gamma (γ) Pure energy (wave) 0 (no change) 0 (no change) 0 (no change)

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✏ Your Teacher's Radiation Questions (Step-by-Step):

Question: An atom has 8p, 8n, 8e (at#=8, atm=16, atch=0). It undergoes ALPHA decay. What are the new at#, atm, and atch?

· Step 1: Apply Alpha changes: p-2, n-2, e-2.

· New p = 8 - 2 = 6

· New n = 8 - 2 = 6

· New e = 8 - 2 = 6

· Step 2: Recalculate the formulas with the NEW numbers!

· New at# = New p = 6

· New atm = New p + New n = 6 + 6 = 12 (dropped by 4!)

· New atch = New p - New e = 6 - 6 = 0

· Final Answer: at#=6, atm=12, atch=0.

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Question: Same atom (8p, 8n, 8e). It undergoes BETA decay. What are the new numbers?

· Step 1: Apply Beta changes: p+1, n-1, e-1.

· New p = 8 + 1 = 9

· New n = 8 - 1 = 7

· New e = 8 - 1 = 7

· Step 2: Recalculate!

· New at# = New p = 9 (went UP by 1)

· New atm = New p + New n = 9 + 7 = 16 (STAYS THE SAME!)

· New atch = New p - New e = 9 - 7 = +2

· Final Answer: at#=9, atm=16, atch=+2.

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Question: Same atom (8p, 8n, 8e). It undergoes GAMMA decay.

· Gamma changes NOTHING.

· Final Answer: at#=8, atm=16, atch=0 (all identical).

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🧠 YOUR CHEAT SHEET FOR THE EXAM (The Short Version)

· at# = just Protons.

· atm = Protons + Neutrons.

· atch = Protons - Electrons.

· Alpha → atm drops by 4, at# drops by 2.

· Beta → atm stays the SAME, at# goes UP by 1.

· Gamma → changes NOTHING.

Quick ID for Rocks:

· Crystals visible? → Igneous Intrusive (Granite).

· Fossils or layers? → Sedimentary.

· Bands or very hard/changed? → Metamorphic.