Explanation

Primary pollutants are emitted directly into the air from sources like vehicles and industries.

Examples include carbon monoxide (CO), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂).

Explanation

Molarity (M) is defined as the number of moles of solute per liter of solution.

It is widely used in chemistry to express solution concentration.

Explanation

pH is calculated as pH = -log[H⁺].

For [H⁺] = 1 × 10⁻⁷ M, pH = 7 → the solution is neutral.

Explanation

John Dalton proposed the Atomic Theory of Matter in 1803.

He stating that all matter is made up of tiny indivisible particles called atoms.

Explanation

Fragrance spreads because its molecules move from a region of high concentration to low concentration in air.

This natural mixing of particles without external force is called diffusion.

Explanation

Radon (Rn) is a radioactive gas formed from the decay of uranium and radium found in rocks and soil.

He (Helium): Helium is present in trace amounts in the atmosphere.

Ne (Neon): Neon is also present in trace amounts in the atmosphere.

Ar (Argon): Argon is the most abundant noble gas in Earth's atmosphere, making up about 0.93% of the air. 

Explanation

• An exothermic reaction releases energy into the surroundings as heat or light.
• Heat released: Energy moves outward.
• Surroundings warm: Temperature rises.
• Negative enthalpy: Delta H < 0
• Lower product energy: Reactants hold more energy.

Additional information:

• In an endothermic reaction, heat is absorbed from the surroundings.
• Examples include photosynthesis and melting of ice.

Explanation

Plaster of Paris (POP) is calcium sulfate hemihydrate (CaSO₄·½H₂O).  

It is made by heating gypsum (CaSO₄·2H₂O) to remove water partially.

Explanation

Explanation

Biotic components are the living organisms in an ecosystem, including plants, animals, fungi, and microorganisms.

They interact with each other and with abiotic components (like water, soil, air) to sustain the ecosystem.