Faraday's law of electromagnetic induction:

1. Whenever there is a change in magnetic flux linked with a coil,an emf is induced,which lasts as long as the change inmagnetic flux is linked with the coil changes.
2. The magnitude of the induced emf is directly proportional to the rate of change magnitude flux linked with the coil.

LED lamps are more energy-efficient as they consume significantly less power and last longer compared to incandescent lamps.

After the emission of an α-particle:

• Protons: 92 - 2 = 90
• Neutrons: 143 - 2 = 141

The new atom will have 90 protons and 141 neutrons.

The energy of stars is primarily produced by nuclear fusion reactions.

Mendeleev's contributions to the creation of the periodic table include:

1. Periodic Law: He arranged elements in order of increasing atomic mass and discovered that elements with similar properties appeared at regular intervals (periodicity).
2. Predictions: Mendeleev left gaps in the table for undiscovered elements and accurately predicted their properties, such as gallium and germanium.
3. Grouping of Elements: He successfully grouped elements with similar chemical properties into columns, establishing the foundation for the modern periodic table.

OR

The atomic radius of an atom is the distance from the center of the nucleus to the outermost shell of electrons. It represents the size of the atom.

For group 14 elements (C, Si, Ge):

C < Si < Ge

Two Classes of Electrolytes:

1. Strong Electrolytes: Completely dissociate into ions in solution (e.g., sodium chloride, hydrochloric acid).
2. Weak Electrolytes: Partially dissociate into ions in solution (e.g., acetic acid, ammonium hydroxide).

Differentiation:

• Strong Electrolytes conduct electricity well due to full ionization.
• Weak Electrolytes conduct electricity poorly because they only partially ionize

Balanced Chemical Equation for the Haber Process: 

N₂ (g) + 3H₂ ​ (g) ⇌ 2NH₃ ​ (g)

Conditions of the Process:

1. Temperature: Approximately 450°C.
2. Pressure: Around 200 atmospheres.
3. Catalyst: Finely divided iron with promoters like potassium and aluminium oxides or molybdenum.

The hydrocarbon is methane (CH₄).

Balanced Chemical Equation for the First Step:

CH₄+ Cl₂ {\overset{\text{diffused sunlight}}{\longrightarrow}}  CH₃ + HCl

In this reaction, methane reacts with chlorine to form methyl chloride (CH₃Cl) and hydrogen chloride (HCl).

Use of Methane:

Methane is widely used as a fuel in domestic and industrial applications due to its high energy content.

OR

The primary industrial sources of LPG (Liquefied Petroleum Gas) are natural gas processing and crude oil refining.

Uses:

1. Acetic Acid: Used as a preservative and flavouring agent in food (e.g., vinegar).
2. Poly (tetrafluoroethylene): Commonly known as Teflon, it is used as a non-stick coating for cookware.

Carbon dioxide.

PV = nRT

= 1 × 0.082 × 273

= 22.4 atm L.

DC (Direct Current) is a type of electric current that flows in a single, constant direction. In a DC circuit, the electric charge (current) does not change direction.

γ-rays.

The structural formula of ethane:

Importance of Insulators in Household Wiring:

1. Safety: Prevents electric shock.
2. Prevents Short Circuits: Avoids electrical fires.
3. Efficiency: Reduces energy loss.
4. Durability: Protects against moisture and corrosion.