Resistance (r) of each part = 10\over2 = 5 Ω

Equivalent Resistance (R) = r × r\over r + r

= 5 × 5\over 5 + 5

= 2.5 Ω

OR

Energy consumed per day

By lamp = 2 × 60 × 5  = 600 Wh

By fan    = 2 × 80 × 5 = 800 Wh

Total energy consumed per day = 600 + 800 = 1400 Wh

Energy consumed in one month = 1400 × 30

= 42000 Wh

= 42 kWh or 42 BOT

Comparison of α and γ Rays:

1. Charge:

• α Rays: These are positively charged particles (helium nuclei) consisting of 2 protons and 2 neutrons.
• γ Rays: These are uncharged electromagnetic waves (gamma photons) and carry no electrical charge.

Ionizing Power:

• α Rays: Have high ionizing power. They ionize atoms more effectively because they are heavier and carry a charge. They can cause significant ionization in a small volume.
• γ Rays: Have low ionizing power. They penetrate materials more deeply but ionize fewer atoms along their path compared to α rays.

One use of radioactivity is in nuclear medicine for diagnostic imaging (e.g., PET scans) and treatment (e.g., radiotherapy for cancer).

Ionization energy is the amount of energy required to remove an electron from an atom or ion in its gaseous state to form a positively charged ion.

Increasing Order: Rb < K < Na < Li

OR

Similarity of Properties of Hydrogen:

With Group 1 Elements:

• Formation of Hydrides: Like alkali metals (Group 1), hydrogen forms hydrides (e.g., H₂O with oxygen, similar to how alkali metals form metal hydrides).

With Group 17 Elements:

• Formation of Acids: Hydrogen forms acids with halogens (Group 17 elements) such as HCl, HBr, and HI, similar to halogens forming hydrogen halides.
• Electron Configuration: Both hydrogen and halogens have a tendency to gain or share one electron to achieve a stable electronic configuration.

In the extraction of aluminium by electrolysis, cryolite (Na₃AlF₆) is added to the molten alumina (Al₂O₃). Cryolite lowers the melting point of the alumina and increases its conductivity, which makes the electrolytic process more efficient.

• Cathode: Carbon coating in the inner wall.
• Anode: Carbon rods.

Conditions for the Industrial Production of Ammonia by Haber’s Process:

1. Temperature: Typically around 450-500°C.
2. Pressure: Approximately 200-300 atmospheres.
3. Catalyst: Iron (Fe) with Molybdenum (Mo) as a promoter.
4. Reactants: Nitrogen (N₂) and hydrogen (H₂).

Balanced Chemical Equation:

N₂ (g) + 3H₂ (g) → 2NH₃ (g)

In this process, nitrogen and hydrogen gases react in the presence of an iron catalyst at high temperature and pressure to produce ammonia gas.

Identification of the Organic Compound: The compound with the molecular formula C₂H₄O₂ is acetic acid (CH₃COOH). It is soluble in water and reacts with sodium bicarbonate (NaHCO₃) to release carbon dioxide (CO₂), indicating it is a carboxylic acid.

Reaction with Ethanol:

Acetic acid reacts with ethanol in the presence of a catalyst (usually sulfuric acid) to form ethyl acetate through an esterification reaction.

Balanced Chemical Equation:

CH₃COOH + CH₃CH₂OH → CH₃​COOC_2​H₅​ + H₂​O

OR

Comparison of Properties of Organic and Inorganic Compounds:

Storms occur in the troposphere.

The alkaline earth metals are placed in Group 2 of the periodic table.

The two resistances must be connected in parallel.

The gas that smells like rotten eggs is hydrogen sulfide (H₂S).

The product of pressure and volume of 2 g of hydrogen at STP is 22.4 L·atm.

One common ore of copper is copper pyrites, also known as chalcopyrite.

• Name: Chalcopyrite
• Formula: CuFeS₂