In an aquarium the water quantity is limited and fish excrete ammonia through their gills and body, this dissolves in water and creates toxins.
<u>Explanation</u>:
- In an aquarium the water quantity is limited and fish excrete ammonia through their gills and body, this dissolves in water and creates toxins. Over some time some bacteria develop in water which converts this ammonia into nitrites and then into nitrates. Till this process is complete, the aquarium remains a death trap.
There are some reasons for a fish to die early,
- This one is common for beginners. They don’t have any idea about the nitrogen cycle. And they simply buy a fish tank and fish on the same day, go home and set it up.
- Ammonia spikes - Even in a cycled tank, you can have occasional ammonia spikes due to overfeeding. Incompatible tank mates - If you put a too docile fish with a very aggressive cichlid, it will get harassed and eventually die due to stress.
Energy can accomplish work
the answer is the nature of science
The question is incomplete, here is the complete question:
Write a balanced chemical equation for each single replacement reaction that takes place in aqueous solution. write no reaction if a reaction does not occur
1.) Zn + PbCl₂
2.) Cu + Fe(NO₃)₂
<u>Answer:</u>
<u>For 1:</u> The reaction does occur.
<u>For 2:</u> The reaction does not occur.
<u>Explanation:</u>
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.

For the given options:
Zinc is more reactive than lead as it lies above in the series. So, it will displace lead from its chemical equation.
The chemical equation for the reaction of zinc and lead chloride follows:

Copper is less reactive than iron as it lies below in the series. So, it will not displace iron from its chemical equation.
The chemical equation for the reaction of copper and iron (II) nitrate follows:
