Answer the following question given this paragraph: Pure Substances and Mixtures A pure chemical substance is any matter that has a fixed chemical composition and characteristic properties. Oxygen, for example, is a pure chemical substance that is a colorless, odorless gas at 25C. Very few samples of matter consist of pure substances; instead, most are mixtures, which are combinations of two or more pure substances in variable proportions in which the individual substances retain their identity. Air, tap water, milk, blue cheese, bread, and dirt are all mixtures. If all portions of a material are in the same state, have no visible boundaries, and are uniform throughout, then the material is homogeneous. Examples of homogeneous mixtures are the air we breathe. Q: What type of substance is any matter that has a fixed chemical composition and characteristic properties? Choices: - physical substance - versatile chemical substance - seawater chemical substance - pure chemical substance A:
pure chemical substance
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Answer the following question given this paragraph: After a star becomes a red giant, it will take one of several different paths to end its life. Which path is followed by a star after the red giant phase depends on its mass. During the fusion life of a star, its size is the result of a competition between fusion heat pushing the material out and gravity pulling the material in. At the end, gravity always wins. After the star has lived through its red giant stage, the fusion essentially ends (the star runs out of fuel) allowing gravity to collapse the star. Some of the outer layers of material will be blown away and the core becomes smaller and denser. The core will become either a neutron star, a white dwarf, a black dwarf, or a black hole. Q: After what life stage does the fusion inside a star end? Choices: - blue giant - yellow dwarf - white dwarf - red giant A:
red giant
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Answer the following question given this paragraph: It can be. Achondroplasia is the most common form of dwarfism in humans, and it is caused by a dominant mutation. The mutation can be passed from one generation to the next. Over 95% of unrelated individuals with Achondroplasia have the same mutation, making it one of the most common mutations in the human genome. Why?. Q: What is the most common form of dwarfism in humans? Choices: - anemia - alopecia - malnutrition - achondroplasia A:
achondroplasia
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Answer the following question given this paragraph: Ionic compounds consist of oppositely charged ions that are held together by ionic bonds. The opposite charges cancel out so ionic compounds have a net neutral charge. Ionic compounds form when metals transfer valence electrons to nonmetals. Q: What kind of charge do iconic compounds have? Choices: - net negative charge - net positive charge - white neutral charge - net neutral charge A:
net neutral charge
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