Answer:
D
Explanation:
1.) The reaction is at dynamic equilibrium.
A: Nitrogen and hydrogen combine at the same rate that ammonia breaks down.
2.) Which statement about the reaction is necessarily correct?
A: Both calcium carbonate and sodium carbonate are being produced.
3.) Both calcium carbonate and sodium carbonate are being produced.
A: The reaction is reversible.
4.) What is the fastest motion that can be measured in any frame of reference?
A: 300,000 km/s
5.) Two people are on a train that is moving at 10 m/s north. They are walking 1 m/s south relative to the train. Relative to the ground, their motion is 9 m/s north.
Why are we able to use these motions to describe the motion relative to the ground?
A: The people are moving much slower than the speed of light so the ground acts as a frame of reference.
Answer:
They are known as isotopes
Answer:
Explanation:
When a ray of light passes through denser medium to rarer medium and then after refraction it comes back into the denser medium, the phenomenon is called total internal refraction.
There are two necessary conditions for the total internal refraction.
(1) The refraction takes place g=from denser medium to rarer medium.
(2) The angle of incidence in the denser medium should be more than the critical angle for that pair of media.
Answer:
The value is 
Explanation:
From the question we are told that
Generally the average velocity of the train is mathematically represented as

substituting 82.4 km/h for u and 16.4 km/h. for v


Generally the time taken is mathematically represented as

substituting 49.4 \ km/h for v and 


converting to seconds


True. I think.................