የምዕራፍ ማስታወሻዎችና የመልመጃ ጥያቄዎች

የ9ኛ ክፍል ኬሚስትሪ ምዕራፍ 3፦ የአተም መዋቅር

በዚህ ገጽ ያለው ሁሉ ለ9ኛ ክፍል የኬሚስትሪ መፅሐፍ ምዕራፍ 3 ነው፦ ምዕራፉ የሚሸፍነው፣ አጭር ማስታወሻዎቹ፣ የመልመጃ ጥያቄዎች ከመልሶቻቸው ጋር፣ እና ቪዲዮ ባለበት የትምህርቱ ቪዲዮ።

5
ካርዶች: 10
የምዕራፍ 3 የመልመጃ ጥያቄዎች: 53–110
የምዕራፍ 3 የመፅሐፍ ገጾች

ምዕራፍ 3 የሚሸፍነው

1.Historical Development of the Atomic
2.Fundamental Laws of Chemical Reactions
3.Atomic Theory
4.Discoveries of Fundamental Subatomic
5.Composition of an Atom and the Isotopes

የምዕራፍ 3 አጭር ማስታወሻዎች

በ9ኛ ክፍል የኬሚስትሪ ገጽ ላይ በዚህ ምዕራፍ ሥር የተመዘገቡት ካርዶች። አንድ በአንድ ይክፈቱ።

የመሠረታዊ ንዑሳን-አቶም ቅንጣቶች ግኝትየማጣቀሻ ሠንጠረዥCathode rays (electrons) · Anode rays (protons)

ጨረር / ቅንጣት	የተገኘው በ	ዋና ዋና ባሕርያት
Cathode rays (electrons)	J. J. Thomson (1897)	በቀጥታ መስመሮች ይጓዛሉ፣ paddle wheels ያሽከረክራሉ፣ ወደ positive electric plates ያዘነብላሉ፣ በ gas ዓይነት ላይ አይመሰረቱም።
Anode rays (protons)	Eugene Goldstein (1886)	ቀዳዳ ባላቸው cathodes ውስጥ ይጓዛሉ፣ ወደ negative plates ያዘነብላሉ፣ ባህሪያቸው እና e/m ratio በ gas ላይ ይመሰረታሉ።

መቼ እንደሚጠቀሙበት

የካቶድ እና የአኖድ ጨረሮች ታሪካዊ ሙከራዎችን እና ባሕርያትን ለመከለስ ይጠቀሙበት።

ይጠንቀቁ

የካቶድ ጨረር ባሕርያት በቱቦው ውስጥ ባለው የጋዝ ዓይነት አይለወጡም፤ ነገር ግን የአኖድ ጨረሮች ባሕርይ እና የሙላት-ለግዙፈቁስ ንፅፅር በጋዙ ዓይነት ላይ የተመሠረተ ነው።

ከGrade 9 Chemistry፣ ገጽ 53-110 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

የኬሚካል ምላሾች መሠረታዊ ሕጎችየማጣቀሻ ሠንጠረዥLaw of Conservation of Mass · Law of Definite Proportions · Law of Multiple Proportions

ሕግ	ሳይንቲስት	ዋና መርህ
Law of Conservation of Mass	Antoine Lavoisier (1789)	በ chemical reaction ወቅት mass አይፈጠርም ወይም አይጠፋም።
Law of Definite Proportions	Joseph Louis Proust (1799)	አንድ compound ሁልጊዜ ተመሳሳይ elements ን በ mass ቋሚ proportion ይይዛል።
Law of Multiple Proportions	John Dalton	ከሌላው ቋሚ mass ጋር የሚጣመሩ የአንድ element masses በትንሽ whole-number ratios ውስጥ ናቸው።

መቼ እንደሚጠቀሙበት

የኬሚካል ውህደትን የሚመሩ የሙከራ ሕጎችን ለመለየት ወይም ለማወዳደር ይጠቀሙበት።

ይጠንቀቁ

Law of Definite Proportions ለአንድ ውህድ ብቻ የሚሠራ ሲሆን፣ Law of Multiple Proportions ግን ከተመሳሳይ ንጥረ ነገሮች በተፈጠሩ ሁለት ወይም ከዚያ በላይ የተለያዩ ውህዶች መካከል ያለውን ንጽጽር ያሳያል።

ከGrade 9 Chemistry፣ ገጽ 53-110 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

የሞል ቁጥር ስሌትቀመር

n = \frac{m}{M}

n = \frac{m}{M}

$n$: የሞል ቁጥር $\text{mol}$
$m$: የተሰጠ መጠነ ቁስ $\text{g}$
$M$: ሞለኪውላዊ መጠነ ቁስ $\text{g}\,\text{mol}^{-1}$

መቼ እንደሚጠቀሙበት

ከተሰጠው ግዙፈ ቁስ እና ሞለኪውላር ግዙፈ ቁስ በመነሳት የንጥረ ነገሩን መጠን በሞል ለማስላት ይጠቀሙበት።

ይጠንቀቁ

የተሰጠው ግዙፈ ቁስ በግራም መሆኑን ያረጋግጡ፤ አለበለዚያ ከሞለኪውላር ግዙፈ ቁስ አሃድ ጋር በቀላሉ አይጣፋም።

ከGrade 9 Chemistry፣ ገጽ 53-110 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

የAverage Atomic Mass ስሌትቀመር

m_{\text{avg}} = \frac{p_1 m_1 + p_2 m_2}{100}

m_{\text{avg}} = \frac{p_1 m_1 + p_2 m_2}{100}

$m_{\text{avg}}$: የንጥረ ነገሩ Average Atomic Mass $\text{amu}$
$p_1$: የመጀመሪያው isotope መቶኛ መጠን $\%$
$m_1$: የመጀመሪያው isotope atomic mass $\text{amu}$
$p_2$: የሁለተኛው isotope መቶኛ መጠን $\%$
$m_2$: የሁለተኛው isotope atomic mass $\text{amu}$

መቼ እንደሚጠቀሙበት

የአንድን ንጥረ ነገር average atomic mass ከisotopes ክብደትና የተፈጥሮ መቶኛ መጠን ለማስላት ይጠቀሙበት።

ይጠንቀቁ

የመቶኛ እሴቶችን በቀጥታ ከተጠቀሙ ድምሩን ለ100 ማካፈልን አይርሱ።

ከGrade 9 Chemistry፣ ገጽ 111-142 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

የMass Number ስሌትቀመር

A = Z + N

A = Z + N

$A$: Mass number፡ የprotons እና neutrons ጠቅላላ ድምር $1$
$Z$: Atomic number፡ በnucleus ውስጥ የሚገኙ protons ብዛት $1$
$N$: በnucleus ውስጥ የሚገኙ neutrons ብዛት $1$

መቼ እንደሚጠቀሙበት

የአንድን አቶም mass number፣ atomic number ወይም የneutrons ብዛት ለማስላት ይጠቀሙበት።

ይጠንቀቁ

Electrons በmass number ውስጥ አይካተቱም። Mass number የprotons እና neutrons ድምር ብቻ ነው።

ከGrade 9 Chemistry፣ ገጽ 111-142 የተዘጋጀ፤ ከመውጣቱ በፊት ሁለት ጊዜ ተረጋግጧል

የምዕራፍ 3 የመልመጃ ጥያቄዎች

በዚህ ምዕራፍ ላይ የተጻፉ 10 የምርጫ ጥያቄዎች፣ እያንዳንዳቸው መልሱና ምክንያቱ አላቸው። መልሱን ከመክፈትዎ በፊት ይሞክሩ። ጥያቄዎቹ በእንግሊዝኛ ናቸው።

ጥያቄ 1

The word atom comes from the ancient Greek word atomos, which means:

A.Uncuttable or indivisible
B.Positively charged
C.Liquid substance
D.Continuous matter

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A Uncuttable or indivisible

ምክንያቱ

In Greek, the prefix a- means 'not' and tomos means 'cut'. Therefore, atomos means uncuttable or indivisible.

ጥያቄ 2

According to the ancient Greek philosopher Empedocles, all materials are made up of which four elements?

A.Earth, air, water, and fire
B.Gold, silver, iron, and copper
C.Wood, stone, salt, and clay
D.Carbon, hydrogen, oxygen, and nitrogen

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A Earth, air, water, and fire

ምክንያቱ

Empedocles proposed that all materials in the universe are formed from four basic elements: earth, air, water, and fire.

ጥያቄ 3

Which scientist discovered the electron in 1897 using a cathode ray tube?

A.J. J. Thomson
B.John Dalton
C.James Chadwick
D.Ernest Rutherford

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A J. J. Thomson

ምክንያቱ

The British physicist J. J. Thomson discovered the electron in 1897 and determined its charge-to-mass ratio using cathode ray experiments.

ጥያቄ 4

Who discovered the Law of Conservation of Mass in 1789?

A.Antoine Lavoisier
B.Joseph Louis Proust
C.John Dalton
D.Niels Bohr

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A Antoine Lavoisier

ምክንያቱ

Antoine Lavoisier discovered the Law of Conservation of Mass in 1789 by showing that mass is neither created nor destroyed during chemical reactions.

ጥያቄ 5

In a laboratory in Hawassa, a chemistry student reacts 224.4 g of potassium hydroxide (KOH) with 88.0 g of carbon dioxide (CO₂). If 36.0 g of water is formed, what mass of potassium carbonate (K₂CO₃) is produced?

A.276.4 g
B.312.4 g
C.136.4 g
D.348.4 g

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A 276.4 g

ምክንያቱ

By the Law of Conservation of Mass, total mass of reactants equals total mass of products. Total reactants = 224.4 g + 88.0 g = 312.4 g. Mass of K₂CO₃ = 312.4 g - 36.0 g = 276.4 g.

ጥያቄ 6

What modification did Eugen Goldstein make to the cathode ray tube in 1886 to discover canal rays (anode rays)?

A.He used a perforated cathode
B.He inserted a rotating paddle wheel
C.He removed all electric electrodes
D.He replaced the glass tube with a metal box

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A He used a perforated cathode

ምክንያቱ

Goldstein used a cathode with small holes (a perforated cathode), which allowed positively charged rays to pass through and produce a glow behind the cathode.

ጥያቄ 7

When J. J. Thomson placed a light paddle wheel between the cathode and the anode, the paddle wheel rotated. What did this show about cathode rays?

A.They consist of material particles having mass and kinetic energy
B.They are composed purely of light waves with no mass
C.They carry a positive electrical charge
D.They can only travel in circular paths

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A They consist of material particles having mass and kinetic energy

ምክንያቱ

The rotation of the paddle wheel showed that cathode rays have particulate nature, meaning they are material particles that carry mass and kinetic energy.

ጥያቄ 8

Dalton believed that atoms of different elements always have different masses. Which pair of elements disproves this by having the same mass number of 40 amu (isobars)?

A.Argon and calcium
B.Carbon and oxygen
C.Hydrogen and helium
D.Sodium and chlorine

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A Argon and calcium

ምክንያቱ

Argon and calcium are isobars because both have an atomic mass of 40 amu, proving that atoms of different elements can sometimes have the same mass.

ጥያቄ 9

Nitrogen forms different compounds with oxygen. In one compound, 2.62 g of nitrogen combines with 1.50 g of oxygen. In a second compound, 0.656 g of nitrogen combines with 1.50 g of oxygen. What is the small whole-number ratio of nitrogen masses combining with the fixed mass of oxygen?

A.4:1
B.2:1
C.3:1
D.1:2

መልሱንና ምክንያቱን ያሳዩ

መልስ፦ A 4:1

ምክንያቱ

Divide the larger mass of nitrogen by the smaller mass: 2.62 / 0.656 = 4. This gives a small whole-number ratio of 4:1, demonstrating the Law of Multiple Proportions.

ጥያቄ 10

According to the historical timeline of atomic discoveries in the textbook, which subatomic particle was discovered by James Chadwick in 1932?