Questions:
Questions: 1. What is the main purpose of the passage? A) To compare radiocarbon dating with other dating methods B) To explain how radiocarbon dating works and note its limitations C) To argue that radiocarbon dating is the most important archaeological tool D) To describe Willard Libby's career and achievements 2. According to the passage, why does the ratio of carbon-14 to carbon-12 remain constant in a living organism? A) Because carbon-14 does not decay in living tissue B) Because the organism absorbs new carbon-14 faster than it decays C) Because the organism continuously exchanges carbon with its surroundings D) Because stable carbon-12 converts into carbon-14 over time 3. The word "decays" in the first paragraph is closest in meaning to: A) disappears B) breaks down C) combines D) stabilizes 4. According to the passage, which of the following can be directly dated using radiocarbon dating? A) A stone axe B) A bronze coin C) A piece of charcoal D) A clay pottery shard 5. Why do raw radiocarbon dates need to be calibrated? A) Because instruments for measuring carbon-14 are not precise enough B) Because atmospheric carbon-14 levels have varied over time C) Because the half-life of carbon-14 has changed over millennia D) Because different organisms absorb carbon at different rates 6. What can be inferred about materials older than 50,000 years? A) They contain no carbon-14 at all B) They require a different isotope for accurate dating C) They cannot be reliably dated using radiocarbon dating D) They can only be dated using tree ring records 7. Which sentence below best expresses the essential information in the following sentence from the passage? Upon death, however, this exchange stops, and the carbon-14 begins to decay at a known rate - its half-life is approximately 5,730 years. A) When an organism dies, it stops absorbing carbon, and its carbon-14 decreases at a predictable speed, with half of it gone every 5,730 years. B) After death, the organism's carbon-14 level stays the same for 5,730 years and then suddenly drops. C) The half-life of carbon-14 means that all of it disappears after 5,730 years following an organism's death. D) When an organism dies, it continues to exchange carbon for 5,730 years before the decay process begins.