Ques:Q: Unlike pure substances, mixtures have a what? Read this paragraph and choose the correct option from the provided answers: When two or more pure substances are combined together, a mixture is formed. Unlike pure substances, mixtures have a variable composition. Variable composition indicates that the relative proportions of the mixtures components may vary, and they can be separated by physical methods. There are two main types of mixtures. Choices: - efficient composition - unique composition - complex composition - variable composition A:

Ans:variable composition
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Ques:Q: Quantum chromodynamics combines what property with quark theory? Read this paragraph and choose the correct option from the provided answers: Why must hadrons be white? The color scheme is intentionally devised to explain why baryons have three quarks and mesons have a quark and an antiquark. Quark color is thought to be similar to charge, but with more values. An ion, by analogy, exerts much stronger forces than a neutral molecule. When the color of a combination of quarks is white, it is like a neutral atom. The forces a white particle exerts are like the polarization forces in molecules, but in hadrons these leftovers are the strong nuclear force. When a combination of quarks has color other than white, it exerts extremely large forceseven larger than the strong forceand perhaps cannot be stable or permanently separated. This is part of the theory of quark confinement, which explains how quarks can exist and yet never be isolated or directly observed. Finally, an extra quantum number with three values (like those we assign to color) is necessary for quarks to obey the Pauli exclusion principle. Particles such as the , which is ++ composed of three strange quarks, sss , and the , which is three up quarks, uuu, can exist because the quarks have different colors and do not have the same quantum numbers. Color is consistent with all observations and is now widely accepted. Quark theory including color is called quantum chromodynamics (QCD), also named by Gell-Mann. Choices: - mass - contrast - sound - color A:

Ans:color
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Ques:Q: What occurs when the immune system is not working properly? Read this paragraph and choose the correct option from the provided answers: Immunodeficiency occurs when the immune system is not working properly. As a result, it cannot fight off pathogens that a normal immune system would be able to resist. Rarely, the problem is caused by a defective gene. More often, it is acquired during a person's lifetime. Immunodeficiency may occur for a variety of reasons:. Choices: - allergy - cancer - anemia - immunodeficiency A:

Ans:immunodeficiency
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Ques:Q: How long does membrane depoloriazation typically last for? Read this paragraph and choose the correct option from the provided answers: Choices: - 1 hour - 3 seconds - 5 minutes - one minute A:

Ans:
one minute
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