Tag: science & technology

Carbon monoxide binds to hemoglobin 200+ times more strongly than oxygen, causing hypoxia and tissue damage. CO2, SO2, and SO3 are respiratory irritants but don't enter bloodstream as efficiently. CO is called the silent killer for this reason.

Nicolaus Copernicus formulated the heliocentric model in the early 16th century, proposing that the Earth revolves around the Sun rather than being the center of the universe. His work 'De revolutionibus orbium coelestium' (1543) fundamentally changed astronomy. Kepler later refined this with elliptical orbits, while Galileo provided observational evidence.

Ammonia (NH3) has thermodynamic properties that make it an effective refrigerant, including a high latent heat of vaporization. It was widely used in early refrigeration systems and is still used in industrial applications today due to its efficiency. CO2 and chlorine are not effective refrigerants, while H2S is toxic and not used for this purpose.

There are 20 standard amino acids that are genetically encoded and incorporated into proteins during translation. These are the naturally occurring building blocks of proteins in all living organisms. Each has a distinct side chain that determines its chemical properties. The numbers 12, 15, and 25 are incorrect counts.

Scorpions and spiders are natural predators that feed on insect pests, making them effective biological control agents. They help maintain ecological balance by preying on harmful insects without the need for chemical pesticides. The other pairs are either not predators (parrots, bees) or not typically used for pest control (dragonfly, wasp, kites, locusts).

Ultraviolet (UV) radiation from the sun penetrates the skin and damages DNA, causing sunburn and increasing skin cancer risk. UVB rays are primarily responsible for sunburn, while UVA rays contribute to skin aging. Infrared radiation heats the skin but doesn't cause sunburn, and visible light doesn't damage skin in this way.

Sake is a Japanese rice wine made from fermented rice grains (specifically, rice polished to remove bran). The brewing process uses koji mold to convert starch to sugar, then yeast ferments it to alcohol. It is not made from grapes (wine), vinegar, or palm sap. The correct answer is indeed rice grains.

Hydrogen fuel produces only water vapor when burned, making it the cleanest fuel option with minimal environmental pollution. Kerosene, coal, and diesel all produce carbon dioxide, other greenhouse gases, and particulate matter that contribute to air pollution and climate change. Hydrogen is considered the ultimate clean fuel for the future.