Answer the following question given this paragraph: Radio waves are used for communicating with spacecraft. A round-trip communication from Earth to Mars takes anywhere from 6 to 42 minutes. What challenges might this present for sending unmanned spacecraft and probes to Mars?. Q: How is communication initiated and maintained with spacecraft? Choices: - sonar - telegraph - wi-fi - radio waves A:
radio waves
(Question)
Answer the following question given this paragraph: All chemical reactions, even exothermic reactions, need a certain amount of energy to get started. This energy is called activation energy . For example, activation energy is needed to start a car. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion of gas won't occur without the spark of energy to begin the reaction. Q: The energy a chemical reaction needs to get started is called what kind of energy? Choices: - function - conduction - fusion - activation A:
(Answer)
activation
Ques: Answer the following question given this paragraph: Distribution of Molecular Speeds The motion of molecules in a gas is random in magnitude and direction for individual molecules, but a gas of many molecules has a predictable distribution of molecular speeds. This distribution is called the Maxwell-Boltzmann distribution, after its originators, who calculated it based on kinetic theory, and has since been confirmed experimentally. (See Figure 13.23. ) The distribution has a long tail, because a few molecules may go several times the rms speed. The most probable speed v p is less than the rms speed. Q: The motion of molecules in a gas is random in magnitude and direction for individual molecules, but a gas of many molecules has a predictable distribution of what, which is called the maxwell-boltzmann distribution? Choices: - molecular size - molecular rate - molecular shape - molecular speeds A:
Ans: molecular speeds
(Q).
Answer the following question given this paragraph: Having polar bonds may make a covalent compound polar. A polar compound is one in which there is a slight difference in charge between opposite ends of the molecule. All polar compounds contain polar bonds. But having polar bonds does not necessarily result in a polar compound. It depends on how the atoms are arranged. This is illustrated in Figure below . Both molecules in the figure contain polar bonds, but only formaldehyde is a polar compound. Why is carbon dioxide nonpolar?. Q: Having polar bonds may make a covalent compound what? Choices: - ionic - negatively charged - neutral - polar A:
(A).
polar
Ques:Answer the following question given this paragraph: Summary The concentration of a species in solution can be determined by quantitative analysis. One such method is a titration, in which a measured volume of a solution of one substance, the titrant, is added to a solution of another substance to determine its concentration. The equivalence point in a titration is the point at which exactly enough reactant has been added for the reaction to go to completion. A standard solution, a solution whose concentration is known precisely, is used to determine the concentration of the titrant. Many titrations, especially those that involve acidbase reactions, rely on an indicator. The point at which a color change is observed is the endpoint, which is close to the equivalence point if the indicator is chosen properly. Q: What helps determine the concentration of a species in a solution? Choices: - technical analysis - qualitative analysis - fundamental analysis - quantitative analysis A:

Ans:quantitative analysis
Ques: Answer the following question given this paragraph: The transmission of nerve impulses between neurons is like the passing of a baton between runners in a relay race. After the first runner races, she passes the baton to the second runner. Then the second runner takes over. Instead of a baton, a neuron passes neurotransmitters to the next neuron. Q: Like a runner passing a baton, the transmission of nerve impulses between neurons depends on what? Choices: - enzymes - axons - receptors - neurotransmitters A:
Ans:
neurotransmitters