𝚔𝚗𝚘𝚠𝚕𝚎𝚍𝚐e 🄷🅄🄱

የ12ኛ ክፍል ፈተና የሚሰጥበት ቀን ይፋ ሆነ።

የሁለተኛ ደረጃ ትምህርት ማጠናቀቂያ ሠርተፊኬት (12ኛ ክፍል ፈተና) ከሰኔ 24 እስከ ሃምሌ 17 ቀን 2018 ዓ/ም ድረስ እንደሚሰጥ የትምህርት ምዘናና ፈተናዎች አገልግሎት አሳውቋል።

በሌላ በኩል ፦

- የሬሜዲያል ፕሮግራም ሀገር አቀፍ ፈተና ከግንቦት 17 እስከ ግንቦት 20 ቀን 2018 ዓ/ም ➡️ ግንቦት 19 ኢድ አልአድሃ

- የቅድመ ምረቃ ትምህርት መውጫ ፈተና ከሰኔ 2 እስከ ሰኔ 12 ቀን 2018 ዓ/ም

- የድህረ ምረቃ ትምህርት መግቢያ ፈተና (NGAT) ከሃምሌ 29 እስከ ሃምሌ 30 ቀን 2018 ዓ/ም

- የመሰረታዊ የንባብና የስሌት ክህሎት ምዘና ጥናትና ምርምር መረጃ መሰብሰብ ከሚያዚያ 26 እስከ ግንቦት 7 ቀን 2018 ዓ/ም ይሰጣል።

ቲክቫህ ኢትዮጵያ
ሚያዚያ 16 ቀን 2018 ዓ.ም

@tikvahethiopia

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🔬 Electrochemistry (continued)

Q6: Which does NOT affect preferential discharge?

A) Position in electrochemical series
B) Concentration of ions
C) Temperature
D) Nature of electrode

Correct: C 🟢
Explanation: 3 factors: 1) Position in series 2) Concentration 3) Electrode nature. Temperature is NOT a factor.

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Q7: In electrolytic conduction:

A) Only electrons move, no chemical change
B) Ions move, chemical changes occur at electrodes
C) Electrons move through electrolyte
D) No transfer of matter

Correct: B 🟢
Explanation: Ions migrate to electrodes and undergo reduction/oxidation. Different from metallic conduction!

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Q8: E°(Fe²⁺/Fe) = -0.44V, E°(Cu²⁺/Cu) = +0.34V. TRUE?

A) Electrons flow Cu → Fe
B) Fe is cathode
C) E°cell = +0.78V
D) Cu²⁺ oxidized

Correct: C 🟢
Explanation: More positive = cathode. Cu²⁺ + 2e⁻ → Cu (cathode). E°cell = 0.34 - (-0.44) = +0.78V

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Q9: Balance redox in acidic medium - which method?

A) Oxidation number only
B) Half-reaction only
C) Both can be used
D) Neither

Correct: C 🟢
Explanation: Both methods work for acidic AND basic media. Half-reaction is great for ionic equations.

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Q10: Corrosion of iron needs:

A) Oxygen only
B) Moisture only
C) Both oxygen AND moisture
D) Acidic medium only

Correct: C 🟢
Explanation: Rusting needs:

• Moisture (electrolyte for ion movement)
• Oxygen (for reduction)
Anode: Fe → Fe²⁺ + 2e⁻
Cathode: O₂ + 2H₂O + 4e⁻ → 4OH⁻

───

✅ Quiz Completed!

📚 Key Points:
• Oxidation = loss of electrons (OIL)
• Reduction = gain of electrons (RIG)
• Galvanic: spontaneous, produces electricity
• Electrolytic: non-spontaneous, consumes electricity
• Faraday: m = ZIt

Good luck with your studies! 💪

15 analogy multiple-choice questions with clear explanations 😊

1. Book : Read :: Food : ?
A. Cook
B. Eat
C. Buy
D. Taste

Answer: B. Eat
Explanation: A book is something you read. Food is something you eat. The relationship is object and its use.


2. Teacher : School :: Doctor : ?
A. Clinic
B. Farm
C. Bank
D. Market

Answer: A. Clinic
Explanation: A teacher works in a school. A doctor works in a clinic (or hospital). The relationship is person and workplace.


3. Bird : Fly :: Fish : ?
A. Swim
B. Walk
C. Run
D. Jump

Answer: A. Swim
Explanation: A bird can fly. A fish can swim. The relationship is animal and its movement.


4. Knife : Cut :: Pen : ?
A. Write
B. Draw
C. Ink
D. Paper

Answer: A. Write
Explanation: A knife is used to cut. A pen is used to write. The relationship is tool and its function.


5. Hot : Cold :: Up : ?
A. Down
B. High
C. Top
D. Over

Answer: A. Down
Explanation: Hot and cold are opposites. Up and down are also opposites.


6. Hand : Glove :: Foot : ?
A. Shoe
B. Sock
C. Sandal
D. Boot

Answer: A. Shoe
Explanation: A glove covers the hand. A shoe covers the foot. The relationship is body part and covering.


7. Puppy : Dog :: Kitten : ?
A. Cat
B. Cow
C. Goat
D. Sheep

Answer: A. Cat
Explanation: A puppy is a young dog. A kitten is a young cat. The relationship is young
and adult animal.


8. Sun : Day :: Moon : ?
A. Night
B. Star
C. Sky
D. Light

Answer: A. Night
Explanation: The sun is seen during the day. The moon is seen at night. The relationship is object and time associated with it.


9. Author : Book :: Painter : ?
A. Wall
B. Brush
C. Painting
D. Color

Answer: C. Painting
Explanation: An author writes a book. A painter creates a painting. The relationship is creator and product.


10. Tree : Forest :: Star : ?
A. Galaxy
B. Sky
C. Sun
D. Light

Answer: A. Galaxy
Explanation: A forest is made of many trees. A galaxy is made of many stars. The relationship is group and its members.


11. Eye : See :: Ear : ?
A. Hear
B. Speak
C. Smell
D. Touch

Answer: A. Hear
Explanation: We use our eyes to see. We use our ears to hear. The relationship is body part and function.


12. King : Queen :: Man : ?
A. Lady
B. Girl
C. Woman
D. Princess

Answer: C. Woman
Explanation: King and queen are male and female versions. Man and woman are male and female versions.


13. Car : Fuel :: Human : ?
A. Water
B. Food
C. Air
D. Sleep

Answer: B. Food
Explanation: A car needs fuel to run. Humans need food for energy. The relationship is source of energy.


14. Hour : Minute :: Kilometer : ?
A. Meter
B. Centimeter
C. Distance
D. Road

Answer: A. Meter
Explanation: An hour is made of minutes. A kilometer is made of meters. The relationship is larger unit and smaller unit.


15. Seed : Plant :: Egg : ?
A. Bird
B. Chicken
C. Nest
D. Animal

Answer: B. Chicken
Explanation: A seed grows into a plant. An egg grows into a chicken. The relationship is beginning stage and final form.

Natural or Social ናቹ?

🔬 Chemistry Grade 12 - Unit 2: Electrochemistry

Q1: In: Zn(s) + Cu²⁺ → Zn²⁺ + Cu
Which is CORRECT?

A) Zn reduced, Cu²⁺ oxidized
B) Zn oxidized, Cu²⁺ reduced
C) Both oxidized
D) Electrons from Cu²⁺ to Zn

Correct: B 🟢
Explanation: Zn loses electrons → oxidized. Cu²⁺ gains electrons → reduced. Electrons flow Zn → Cu²⁺

───

Q2: Oxidation number of Cr in K₂Cr₂O₇?

A) +3
B) +5
C) +6
D) +7

Correct: C 🟢
Explanation: K = +1, O = -2. 2(+1) + 2x + 7(-2) = 0 → 2x = +12 → x = +6

───

Q3: Which is NOT a galvanic cell?

A) Daniel cell
B) Dry cell
C) Electrolytic cell for plating
D) Mercury cell

Correct: C 🟢
Explanation: Galvanic cells generate electricity from spontaneous reactions. Electrolytic cells CONSUME electricity!

───

Q4: Electrolysis of concentrated NaCl (inert electrodes), product at cathode:

A) Na
B) H₂
C) Cl₂
D) NaOH

Correct: B 🟢
Explanation: H⁺ from water discharged (lower reduction potential than Na⁺): 2H₂O + 2e⁻ → H₂ + 2OH⁻

───

Q5: Faraday's 1st Law - mass deposited is proportional to:

A) Current × Time
B) Current² × Time
C) Voltage × Time
D) Current × Voltage

Correct: A 🟢
Explanation: m = ZIt (Z = electrochemical equivalent)

📚 𝐂𝐇𝐄𝐌𝐈𝐒𝐓𝐑𝐘 𝐆𝐑𝐀𝐃𝐄 𝟏𝟐 - 𝐔𝐍𝐈𝐓 𝟐: 𝐄𝐋𝐄𝐂𝐓𝐑𝐎𝐂𝐇𝐄𝐌𝐈𝐒𝐓𝐑𝐘

━━━━━━━━━━━━━━━━━━━━━━━━━━━━

🔬 𝟏. 𝐎𝐗𝐈𝐃𝐀𝐓𝐈𝐎𝐍-𝐑𝐄𝐃𝐔𝐂𝐓𝐈𝐎𝐍 (𝐑𝐄𝐃𝐎𝐗)
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Definition: Redox reactions involve transfer of electrons between substances.

Oxidation: Loss of electrons, increase in oxidation number
Reduction: Gain of electrons, decrease in oxidation number

𝐀) Oxidation Number Rules
• Group 1 elements = +1
• Group 2 elements = +2
• Oxygen = -2 (except in peroxides)
• Hydrogen = +1 (with non-metals)
• Fluorine = -1 always
• Sum = charge of compound

𝐁) Balancing Redox Reactions
• Oxidation number method
• Half-reaction method (preferred for ionic equations)

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🔬 𝟐. 𝐄𝐋𝐄𝐂𝐓𝐑𝐎𝐂𝐇𝐄𝐌𝐈𝐂𝐀𝐋 𝐂𝐄𝐋𝐋𝐒
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𝐀) Galvanic (Voltaic) Cells
• Generate electricity from spontaneous reactions
• Anode = negative, Cathode = positive
• E°cell = E°cathode - E°anode

𝐁) Electrolytic Cells
• Consume electricity to drive non-spontaneous reactions
• Anode = positive, Cathode = negative
• Used in electroplating, electrolysis

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🔬 𝟑. 𝐄𝐋𝐄𝐂𝐓𝐑𝐎𝐋𝐘𝐒𝐈𝐒
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Faraday's Laws:
• m = ZIt (mass deposited)
• 1 Faraday = 96485 C deposits 1 mole of electrons

Preferential Discharge Factors:
• Position in electrochemical series
• Concentration of ions
• Nature of electrode

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🔬 𝟒. 𝐂𝐎𝐑𝐑𝐎𝐒𝐈𝐎𝐍
━━━━━━━━━━━━━━━━━━━━━━━━━━━━
• Requires moisture + oxygen
• Anode: Fe → Fe²⁺ + 2e⁻
• Cathode: O₂ + 2H₂O + 4e⁻ → 4OH⁻
• Prevention: painting, galvanizing, cathodic protection

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🔬 𝟏. 𝐇𝐄𝐀𝐋𝐓𝐇 𝐀𝐍𝐃 𝐃𝐈𝐒𝐄𝐀𝐒𝐄 - 𝐎𝐕𝐄𝐑𝐕𝐈𝐄𝐖
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Definition: Health is a state of complete physical, mental, and social well-being, not merely absence of disease.

Disease: Any deviation from normal health, characterized by specific symptoms and signs.

𝐀) Types of Diseases
• Communicable (Infectious): Caused by pathogens - bacteria, viruses, fungi, parasites
Examples: TB, Malaria, HIV, COVID-19
• Non-communicable (NCD): Not transmitted person-to-person
Examples: Diabetes, Hypertension, Cancer, Heart disease

𝐁) Causes of Diseases
• Pathogens (bacteria, viruses, parasites)
• Genetic factors
• Environmental factors
• Lifestyle factors (diet, exercise, smoking)
• Chemical exposure

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🔬 𝟐. 𝐈𝐍𝐅𝐄𝐂𝐓𝐈𝐎𝐔𝐒 𝐃𝐈𝐒𝐄𝐀𝐒𝐄𝐒
━━━━━━━━━━━━━━━━━━━━━━━━━━━━

𝐀) Transmission Modes
• Airborne: Influenza, TB, Measles
• Water/Foodborne: Cholera, Typhoid
• Vector-borne: Malaria (mosquito), Leishmaniasis (sandfly)
• Direct contact: HIV, Herpes
• Sexual transmission: HIV, Hepatitis B

𝐁) Major Infectious Diseases in Ethiopia
• Malaria: Caused by Plasmodium (P. falciparum, P. vivax)
• TB (Tuberculosis): Caused by Mycobacterium tuberculosis
• HIV/AIDS: Human Immunodeficiency Virus
• Neglected tropical diseases: Leishmaniasis, Onchocerciasis

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🔬 𝟑. 𝐈𝐌𝐌𝐔𝐍𝐄 𝐒𝐘𝐒𝐓𝐄𝐌
━━━━━━━━━━━━━━━━━━━━━━━━━━━━

𝐀) Immune Response
• Innate immunity: Non-specific, first line of defense

• Skin, mucous membranes, phagocytes
• Adaptive immunity: Specific, develops after exposure
• B cells (antibodies), T cells (cell-mediated)

𝐁) Antibodies (Immunoglobulins)
• IgG: Most common, crosses placenta
• IgA: Found in mucus, saliva, tears
• IgM: First antibody produced in infection
• IgE: Allergies and parasitic infections
• IgD: Rare, function not fully understood

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🔬 𝟒. 𝐏𝐑𝐄𝐕𝐄𝐍𝐓𝐈𝐎𝐍 𝐀𝐍𝐃 𝐂𝐎𝐍𝐓𝐑𝐎𝐋
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• Vaccination: Most effective prevention method
• Vector control: Mosquito nets, insecticides
• Sanitation: Clean water, proper waste disposal
• Health education: Awareness campaigns
• Early diagnosis and treatment
• Lifestyle modifications: For NCDs

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