Everyday Science

Neptune is the outermost recognized planet in the solar system since Pluto was reclassified as a dwarf planet. Therefore, Neptune is the correct answer.

Nicolaus Copernicus is known as the modern father of astronomy because he formulated the heliocentric model of the solar system, which placed the Sun, rather than the Earth, at the center. This was a revolutionary idea that laid the foundation for modern astronomy.

LPG (Liquefied Petroleum Gas) mainly consists of propane (C3H8) and butane (C4H10) in varying proportions. It may also contain smaller amounts of ethane and other light hydrocarbons, but methane is not a significant component of LPG. Hexane and nonane are not typical constituents of LPG. Therefore, the correct answer is C: Methane, Butane & Propane, although methane is usually minimal or absent in LPG. The question option C is the closest correct choice, and the explanation is updated to clarify that methane is generally minimal or absent in LPG, with propane and butane being the main components.

The ozone layer is primarily composed of ozone molecules, which consist of three oxygen atoms (O3). This layer protects the Earth from harmful ultraviolet radiation.

A total of 12 astronauts have walked on the moon during the six Apollo missions (Apollo 11, 12, 14, 15, 16, and 17). This is a well-documented fact in space exploration history.

Smoke consists of tiny solid particles suspended in a gas (air), making it a solid in gas mixture. Therefore, option C is correct.

The Sun is primarily composed of hydrogen (about 74%) and helium (about 24%), making these two elements its main constituents. Other elements are present only in trace amounts.

The ozone layer is located in the stratosphere, which is the second major layer of Earth's atmosphere above the troposphere. It absorbs most of the Sun's ultraviolet radiation.

Rainbows are formed when sunlight passes through water droplets in the atmosphere, which act like prisms. These droplets refract, reflect, and disperse the light into its constituent colors, creating a spectrum visible as a rainbow.

Pearls are primarily composed of aragonite (a crystalline form of calcium carbonate) and conchiolin, an organic protein that binds the crystals together. This composition gives pearls their characteristic luster and structure.