Answer:
Climate change and an increase in unpredictable and extreme weather is a growing challenge. Long periods of drought affect clean water supplies while flooding can pollute clean water sources and cause outbreaks of disease.
Explanation:
Tollens' reagent is prepared by using two-step process : -
Step 1:
Silver oxide is formed by mixing aqueous silver nitrate with base like sodium hydroxide. The reaction is shown below as:

Step 2
Ammonia solution is drop-wise added until all the silver oxide dissolves to form the reagent. The reaction is shown below as:

Answer:
3 moles of O2 needed
Explanation:
2 moles of Mg to one mole O2
so 3 moles of O2 needed
Hello!
Numbers from -998 and 999 are in between -999 and 1000.
I hope this was helpful! c:
The smaller number is the number of protons, and the greater number is the mass.