a. Bauxite

Explanation: Bauxite is the primary ore from which aluminum is extracted. Hematite is an ore of iron, malachite is an ore of copper, and chalcopyrite is also an ore of copper.

b. -CHO

Explanation: The aldehyde functional group consists of a carbonyl group (C=O) bonded to a hydrogen atom, giving the structure -CHO. The group >C=O represents the carbonyl group, which is also found in ketones.

In the troposphere, temperature decreases with an increase in altitude.

Or

One harmful effect of global warming

1. Rising Sea Levels: Melting polar ice and thermal expansion of seawater lead to coastal flooding and erosion.
2. Extreme Weather Events: Increased frequency and intensity of hurricanes, heatwaves, and heavy rainfall.  (Any one point)

Chlorine atoms, released from chlorofluorocarbons (CFCs) under the influence of UV rays, decompose ozone (O₃) into oxygen (O₂).

False.

Explanation: Under the same conditions of temperature and pressure, equal volumes of any gases, including CO₂ and N₂, contain the same number of molecules according to Avogadro's law.

At constant temperature, the volume of the given mass of the gas is inversely proportional to the pressure of the gas.

PV = constant

Between the apparent and real expansion coefficients of a liquid, the real expansion coefficient is its own characteristic.

OR

The SI unit of thermal conductivity is watt per meter-kelvin (W/m·K).

A natural example of the dispersion of light is a rainbow.

A concave lens can rectify myopic (nearsighted) vision.

If the direction of the current is reversed in a Barlow's wheel, the direction of the motion of the wheel will also be reversed.

Work = 1 C × 1 V = 1 joule

So, 1 joule of work has to be done.

A β-particle (beta particle) is emitted from the nucleus of a radioactive atom.

OR

• The new atomic number = 92 - 2 = 90
• The new mass number = 238 - 4 = 234

Thus, the daughter element produced is ₉₀Th²³⁴ (Thorium)