Answer:A air
Explanation:Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. Temperature also affects the speed of sound.
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Answer:
arrangement 2
Explanation:
arrangement 1's spring would broke idek
Complete Question
The complete question is shown on the first uploaded image
Answer:
The work done by the spring is = 
Explanation:
Force = torque × length
Given
F = 9.13 N
length (L) = 5.91 cm = 0.0591 m [Note 1 m = 100 cm ]
considering the formula above
where k denotes torque

Energy Stored 

Answer:
boron
aluminum
gallium
indium
thallium
Explanation:
Any of these could work. Nitrogen has 5 valence electrons so you just needed to pick an element that has 3 valence electrons that nitrogen could borrow. This periodic table shows valence electron counts:
Galaxies are sprawling systems of dust, gas, dark matter, and anywhere from a million to a trillion stars that are held together by gravity. Nearly all large galaxies are thought to also contain supermassive black holes at their centers.