a) These telescopes must make observations above much of the water vapor in the atmosphere because water can block infrared rays.
Explanation:
Ground- based infrared telescopes are placed in a high altitudes dry climates because the telescopes must make observations above much of water vapor since they cut and block them off.
- Telescopes are devices that are used to observe very distant objects.
- An infrared telescope is sensitive to infrared rays.
- Infrared rays are part of the electromagnetic radiations.
- These rays are usually blocked off by the presence of water vapor.
- Desert areas that lacks water vapor in the atmosphere are the most desired for sighting such facilities.
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The compound that will have the lowest freezing point when dissolved in water is 1.0M Mg(NO3)2. That is option 3.
<h3>Comparing the freezing point of solutions</h3>
To compare the freezing points of solution, the total concentration of all the particles when solutes are dissolved in water is determined.
This is an important step to consider because, the greater the concentration of particles, the lower the freezing point will be.
To determine the concentration of all the particles, ionic compounds are alway 2 while covalent compounds are always 1.
- 1.0M NaCl: This compound is ionic (metal with nonmetal), and will dissolve into 2 parts. The total final concentration is (1m)(2)=2m
- 1M NaOH: This compound is ionic and will dissolve into 2 parts. The total final concentration is (1m)(2)=2m.
- 1.0M Mg(NO3)2: This is an ionic compound but contains a polyatomic ions. The total final concentration is 1m(3) = 3m.
- 2M NH3: This is a covalent compound and will remain in a part. The total final concentration is 2m (1)= 2m.
Therefore, since 1.0M Mg(NO3)2 contains the greater concentration of particles, it has lower freezing point.
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Simply put, MA = Force Out / Force in. That's the way it is usually stated. The force out is normally what you need to move. The force in is what you need to supply to get the force out. Most machines will give you an MA of more than 1. Some (like your arm) will give you less than 1 and others (like this one) will give you exactly one.
This one is frictionless, otherwise it would slip into less than one if it had friction.
Answer B
A reservoir serves as a long term storage area for water or nutrients