I) Overgrazing removes protective vegetation, exposing the soil to erosion by wind and water, which washes away nutrient-rich topsoil. It also compacts the soil, reducing water infiltration and aera

a)

i) Overgrazing removes protective vegetation, exposing the soil to erosion by wind and water, which washes away nutrient-rich topsoil. It also compacts the soil, reducing water infiltration and aeration, hindering nutrient cycling.

ii) Crop removal involves harvesting and taking away plant material from the field. This removes the nutrients that the plants absorbed from the soil, leading to a depletion of soil nutrients if not replenished.

iii) Burning vegetation rapidly releases nutrients like nitrogen and sulfur into the atmosphere as gases, making them unavailable to the soil. While some mineral nutrients remain in the ash, they can be easily lost through erosion or leaching, and the organic matter crucial for soil fertility is destroyed.

b)

i) A derived quantity is a physical quantity that is expressed as a combination of two or more fundamental (base) quantities through mathematical operations such as multiplication or division.

ii) The SI unit of each derived quantity is: * α) Weight: Newton (N) * β) Momentum: Kilogram meter per second (kg m/s) * γ) Pressure: Pascal (Pa) or Newton per square meter (N/m²)

c)

i) Three scientists associated with classification of living and non-living things are: * Carolus Linnaeus * Aristotle * Robert Whittaker

ii) One contribution each of two of the scientists named in 6.(c)(i): * Carolus Linnaeus: Developed the system of binomial nomenclature, which gives each species a two-part scientific name, and established a hierarchical classification system. * Robert Whittaker: Proposed the five-kingdom classification system (Monera, Protista, Fungi, Plantae, Animalia) based on cell structure, mode of nutrition, and body organization.

d)

i) Alkene with three carbon atoms (Propene): $\boxed{\text{CH}_2=\text{CH}-\text{CH}_3}$ ii) Alkanoate with two carbon atoms (Methyl methanoate): $\boxed{\text{HCOOCH}_3}$ iii) Alkanol with two carbon atoms (Ethanol): $\boxed{\text{CH}_3\text{CH}_2\text{OH}}$ iv) Alkanoic acid with two carbon atoms (Ethanoic acid): $\boxed{\text{CH}_3\text{COOH}}$