Answer:
compound
Explanation:
"Marble is typically more than 95% calcium carbonate, perhaps even 99% calcium carbonate, and calcium carbonate is a compound. Marble has a good claim to be recognized as a compound."
Answer:

Explanation:
Hello!
In this case, since the average rate of reaction is computed as a change given by:
![r=\frac{\Delta [NH_4NO_2 ]}{\Delta t}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B%5CDelta%20%5BNH_4NO_2%20%5D%7D%7B%5CDelta%20t%7D)
In such a way, given the concentrations at the specified times, we plug them in to obtain:

Whose negative sign means the concentration decreased due to the decomposition.
Best regards!
Answer:
230hz
Explanation:
Hello,
To solve this question, we gave to use the relationship between velocity-frequency-wavelength to find the frequency in this question.
V = Fλ
V = velocity or speed of the wave
F = frequency of the wave
λ = wavelength of the wave
Data;
V = 414m/s
λ = 1.8m
f = ?
V = fλ
f = v/λ
f = 414/1.8
f = 230hz
The frequency of the wave is 230hz