For us to accurately determine what compound
this is, additional info must be given. However I can suggest two compounds
which have molecular mass of about 30.07 g/mol.
1. It could be NO or nitric oxide.
The molecular mass is 16 + 14= 30 g/mol
But if we search the exact weight, it is 30.01 g/mol
2. It could also be (CH3)2 or ethane.
The molecular mass is 2*12+ 6*1= 30 g/mol
But if we search the exact weight, it
is 30.07 g/mol.
<span>So we could say it more likely to to be (CH3)2 </span>
The answer: less frequency, causing the pitch to be lowered.
This is known as the Doppler effect. When you have an object that is producing sound while moving, the side that it is moving towards to will have waves that will become a bit more squished together, while the other side that it is moving away from will have waves that are spaced a bit more apart from each other. The only determining factor in this is the magnitude of the speed, so the faster the object is moving towards or away from you, then the more severe pitch change the object will have.
In this case, it's just asking in general what would happen if the horn was moving away from you while it was giving off sound waves. Therefore, since it is moving away from you, its sound waves are a bit further apart, resulting in a lowered frequency and pitch.
Explanation:
As per Brønsted-Lowry concept of acids and bases, chemical species which donate proton are called Brønsted-Lowry acids.
The chemical species which accept proton are called Brønsted-Lowry base.
(a) 
is Bronsted lowry acid and 
is its conjugate base.
is Bronsted lowry base and 
is its conjugate acid.
(b)
is Bronsted lowry base and HCN is its conjugate acid.
is Bronsted lowry acid and 
is its conjugate base.
(c)
is Bronsted lowry acid and 
is its conjugate base.
Cl^- is Bronsted lowry base and HCl is its conjugate acid.
(d)
is Bronsted lowry acid and 
is its conjugate base.
OH^- is Bronsted lowry base and is its conjugate acid.
(e)
is Bronsted lowry base and OH- is its conjugate acid.
is Bronsted lowry acid and OH- is its conjugate base.
I believe it is sand. <span />
