Answer:
Nickel is extracted from nickel oxide by reduction with carbon. Nickel is a metal which react with atmospheric oxygen which is very reactive in order to protect the inner surface of metal. Carbon extract oxygen which is attached to the nickel in the form of nickel oxide because carbon is more reactive so it made a chemical bonds with oxygen and nickel oxide is converted into a pure nickel.
Stoichiometry is not really hard if you are good with your numbers. All you have to do is pay close attention and follow you teacher because if you don't you will end up like me not knowing what you are doing. Listen and pay real close attention and I can guarantee you it will be just fine!
<span>Kind of substance besides water:
The best example of hydrogen bonding excluding water is DNA. The two strands of polymers are connected by hydrogen bonds between the nucleotide bases</span>.
The given above pretty much states already that with the presence of the calcium carbonate which acts as the buffer will allow the solution to withstand changes in acidity. The greater the amount, the higher chances that it will be able to withstand the said changes. Therefore, if Lake X had greater ppm of CaCO3 then, it will be able to withstand greater amount of acid rain.