Answer the following question given this paragraph: 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. Q: Quantum chromodynamics combines what property with quark theory? Choices: - mass - contrast - sound - color A:
color
Answer the following question given this paragraph: Immunity can also be caused by vaccination. Vaccination is the process of exposing a person to a pathogen on purpose in order to develop immunity. In vaccination, a modified pathogen is usually injected under the skin by a shot. Only part of the pathogen is injected, or a weak or dead pathogen is used. It sounds dangerous, but the shot prepares your body for fighting the pathogen without causing the actual illness. Vaccination triggers an immune response against the injected antigen. The body prepares "memory" cells for use at a later time, in case the antigen is ever encountered again. Essentially, a vaccine imitates an infection, triggering an immune response, without making a person sick. Q: What is the term for the process of exposing a person to a pathogen on purpose in order to develop immunity? Choices: - evacuation - ramping - priming - vaccination A:
vaccination
Q: Answer the following question given this paragraph: The mesosphere has a very low density of gas molecules. Q: What is the concentration of gas molecules in the mesosphere? Choices: - high density - low density - medium density - very low density A:
A: very low density
Question: Answer the following question given this paragraph: The pressure increases dramatically due to large increase in temperature. Q: What needs to happen to temperature to cause pressure to increase dramatically? Choices: - boiling point - no increase - small increase - large increase A:
Answer: large increase
*Question*
Answer the following question given this paragraph: 5. Anthracite is the hardest type of coal because it is metamorphic. Anthracite causes less pollution when it burns. Why do you think that is?. Q: What is the hardest type of coal? Choices: - Bituminous - lignite - peat - anthracite A:
**Answer**
anthracite
Q: Answer the following question given this paragraph: Water is needed by all known forms of life. Q: What is needed by all known forms of life? Choices: - nitrogen - warmth - air - water A:
A: water