Option C: elements produce spectra with only few distinct lines.
The spectra are not continuos and are different for every element. This permits to identify elements.
Answer:

Explanation:
Since the <em>rate constant</em> has units of <em>s⁻¹</em>, you can tell that the order of the reaction is 1.
Hence, the rate law is:
![r=d[A]/dt=-k[A]](https://tex.z-dn.net/?f=r%3Dd%5BA%5D%2Fdt%3D-k%5BA%5D)
Solving that differential equation yields to the well known equation for the rates of a first order chemical reaction:
![[A]=[A]_0e^{-kt}](https://tex.z-dn.net/?f=%5BA%5D%3D%5BA%5D_0e%5E%7B-kt%7D)
You know [A]₀, k, and t, thus you can calculate [A].
![[A]=0.548M\times e^{-3.6\cdot 10^{-4}/s\times99.2s}](https://tex.z-dn.net/?f=%5BA%5D%3D0.548M%5Ctimes%20e%5E%7B-3.6%5Ccdot%2010%5E%7B-4%7D%2Fs%5Ctimes99.2s%7D)
![[A]=0.529M](https://tex.z-dn.net/?f=%5BA%5D%3D0.529M)
The density of the stone is 5 because the formula is mass/volume and the volume is 5 and the mass is 25
Answer:
Explanation:
it is tough question plz give me some time i would give you your ans soon
A local community needs to provide more electricity for its growing population. Currently, the community's electricity needs are met by coal-burning power plants several kilometres away. Citizens are concerned that burning more coal will produce too much air pollution.
Which of the following could be used as an alternative energy resource to help minimise air pollution in this community?
A. hydroelectric energy
B. solar energy
C. wind energy
<u>D. all of these
</u>
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