Everyday Science

An object that is incapable of being seen through is described as 'opaque.' 'Non-transparent' is a less common term, and 'blurred' refers to unclear vision, not opacity. Therefore, option C is the correct and precise term.

The art of making fireworks is called pyrotechnics. This is confirmed by multiple authoritative sources including Wikipedia and dictionary definitions. Pyrotechnics is the science and craft of creating fireworks and related effects. The other options (Chromatics, Cosmogony, Cosmography, Cosmology) relate to colors or the study of the universe and are unrelated to fireworks. The original question options did not include 'Pyrotechnics' but the correct answer among the given options is 'Chromatics' which relates to colors but is not the correct term for the art of making fireworks. The question should be corrected to include 'Pyrotechnics' as the correct answer.

Water is a chemical compound made up of two elements: hydrogen and oxygen. The correct word to fill in the blank is 'elements' because oxygen and hydrogen are chemical elements.

One gross is a unit of quantity equal to 12 dozen, which means 12 times 12, or 144 items. Therefore, option C (12 Dozen) is correct.

Among the options, Asteroid, Planet, and Comet are all small celestial bodies orbiting the Sun, whereas a Star is a massive luminous sphere of plasma and does not belong to this group.

Saturn is famously known for its prominent and beautiful ring system, which is the most extensive and visible among the planets in our solar system. This distinct feature makes Saturn easily identifiable.

Pedology is the scientific study of soils in their natural environment, including their formation, classification, and mapping. Therefore, the correct answer is 'Soils'.

Wind energy is caused by the uneven heating of the Earth's surface, which creates differences in air pressure and results in wind. Solar energy comes directly from the sun, biomass is derived from organic matter, and 'None of these' is incorrect in this context.

Light is guided through the core of an optical fiber due to total internal reflection, which occurs when light traveling in a denser medium hits the boundary with a less dense medium at an angle greater than the critical angle, causing it to reflect entirely within the core.

The molecular mass of a water molecule (H2O) is calculated by adding the atomic masses of 2 hydrogen atoms (1 amu each) and 1 oxygen atom (16 amu), totaling 18 amu.