Q: Q: An alloy is a mixture of metals that has bulk metallic properties different from those of its what? Read this paragraph and choose the correct option from the provided answers: atoms held together by covalent bonds; they tend to be very hard and have high melting points. Metallic solids have unusual properties: in addition to having high thermal and electrical conductivity and being malleable and ductile, they exhibit luster, a shiny surface that reflects light. An alloy is a mixture of metals that has bulk metallic properties different from those of its constituent elements. Alloys can be formed by substituting one metal atom for another of similar size in the lattice (substitutional alloys), by inserting smaller atoms into holes in the metal lattice (interstitial alloys), or by a combination of both. Although the elemental composition of most alloys can vary over wide ranges, certain metals combine in only fixed proportions to form intermetallic compounds with unique properties. Choices: - system elements - nuclear elements - mineral elements - constituent elements A:
A: constituent elements

Q: Q: What is the fluid that carries sperm through the urethra and out of the body, and provides it with nutrients? Read this paragraph and choose the correct option from the provided answers: Semen is the fluid that carries sperm through the urethra and out of the body. In addition to sperm, it contains secretions from the glands. The secretions control pH and provide sperm with nutrients for energy. Choices: - blood - bacteria - yeast - semen A:
A: semen

Q: Q: What term means controlling body temperature within a narrow range from the inside through biochemical or physical means? Read this paragraph and choose the correct option from the provided answers: Both mammals and birds evolved endothermy. Endothermy means controlling body temperature within a narrow range from the inside through biochemical or physical means. For example, on a cold day, an endotherm may produce more body heat by increasing its rate of metabolism. On a hot day, it may give off more heat by increasing blood flow to the surface of the body. That way, some of the heat can radiate into the air from the body's surface. Endothermy requires more energy (and food) than ectothermy. However, it allows the animal to stay active regardless of the temperature outside. You can learn more about how vertebrates regulate their temperature by watching this video: https://www. youtube. com/watch?v=TSUCdLkI474 . Choices: - exothermy - regulation - evaporation - endothermy A:
A: endothermy

Q: Q: What are all of the digits that can be known with certainty in a measurement plus an estimatied last digit called? Read this paragraph and choose the correct option from the provided answers: Significant figures are all of the digits that can be known with certainty in a measurement plus an estimated last digit. Significant figures provide a system to keep track of the limits of the original measurement. To record a measurement, you must write down all the digits actually measured, including measurements of zero, and you must not write down any digit not measured. The only real difficulty with this system is that zeros are sometimes used as measured digits, while other times they are used to locate the decimal point. Choices: - determined figures - important figures - miniature figures - significant figures A:
A: significant figures