Everyday Science

The Moon completes one rotation on its axis approximately every 27.3 days, which is why the same side of the Moon always faces the Earth. This period is known as the sidereal rotation period of the Moon.

Terrestrial planets in the solar system, such as Earth, Mars, Venus, and Mercury, are composed primarily of rock and metal. Therefore, both metal and rock are correct components of their composition.

Tetrafluoroethane (R-134a) is a commonly used refrigerant gas in refrigerators and air conditioners due to its efficiency and safety compared to older refrigerants. It is used to absorb heat and cool the contents inside, such as water.

The Sun is the star at the center of the solar system, around which all the planets, including Earth, Mercury, and Venus, orbit.

The solar wind originates from the Sun's corona, which is the outermost layer of the Sun's atmosphere. The high temperature and pressure in the corona cause particles to escape into space as solar wind.

The moon's surface is constantly bombarded by meteoroids, which are small rocky or metallic bodies traveling through space. Comets are much less frequent, and UV light is radiation, not a physical bombardment. Therefore, meteoroids are the correct answer.

Voyager 1 is the first human-made object to enter interstellar space, having crossed the heliopause in 2012. Apollo 1 and Apollo II were manned lunar missions, and Sputnik was the first artificial satellite but did not leave the solar system.

Trachoma, glaucoma, and cataract are all diseases that affect the eyes. Therefore, the correct answer is 'All of these'.

Jupiter has the maximum number of moons in the solar system, with over 90 confirmed moons, surpassing Saturn, Uranus, and Venus (which has none).

Osmium is the densest naturally occurring element on Earth, with a density of about 22.59 g/cm³, which is higher than platinum, copper, or steel. Therefore, it is the correct answer.