General Science and Astronomy Quiz

Henry Cavendish is credited with the discovery of hydrogen in 1766, when he identified 'inflammable air' produced by reacting acids with metals. The question incorrectly uses 'invented' - scientists discover elements, they don't invent them. Cavendish recognized hydrogen as a distinct substance.

Energy is measured in joules (J) in the SI system. Watt measures power (rate of energy use per second), weber measures magnetic flux, and m/s measures velocity.

Venus rotates clockwise (retrograde rotation) when viewed from above its north pole, opposite to most planets including Earth. It has the slowest rotation period of any planet (243 Earth days). Uranus also has retrograde rotation. Earth, Mars, and Saturn all rotate counter-clockwise.

Diamond is the purest natural form of carbon, with atoms arranged in a perfect tetrahedral crystal lattice structure. While graphite is also pure carbon, diamond has a more compact and perfect arrangement. Coal and carbon black contain significant impurities and are not pure carbon.

Neptune is the odd one out because it's an outer solar system ice giant, while Earth, Mars, and Venus are all terrestrial (rocky) planets in the inner solar system. Neptune's composition, size, and distance from the sun make it fundamentally different from the other three.

Cuba's principal agricultural product has historically been sugarcane, not tobacco. While tobacco is indeed famous (Cuban cigars are world-renowned) and economically important, sugarcane has been Cuba's dominant crop and the backbone of its agricultural economy for centuries. The statement is therefore false.

The Asian Giant Hornet (Vespa mandarinia), commonly called the Japanese Giant Hornet, is indeed the largest hornet species in the world. Native to East Asia, these hornets can grow up to 5 cm in length. The other countries listed (China, North Korea, South Korea) also have populations, but 'Japanese Giant Hornet' is the specific common name referenced.

Neptune takes approximately 165 Earth years to complete one orbit around the Sun. Mars takes about 687 Earth days (1.88 years). Earth takes 1 year. Pluto takes about 248 Earth years. Neptune is the correct answer.

A star's color directly indicates its surface temperature through blackbody radiation. Hotter stars appear blue/white (surface temperatures above 10,000K), moderately hot stars appear yellow (like our Sun at ~5,800K), and cooler stars appear red (below 3,500K). This relationship is described by Wien's displacement law.