Answer:
The correct answer is option D.
Explanation:
Step 1: 
Step 2: 
Overall reaction can be determined by adding all the reactions of mechanism:

Reactants in an overall reaction = 
Products in an overall reaction = 
According to question , the role of oxygen gas is product.
Answer:
Plants
Explanation:
Plants, part of the biosphere, grow in the soil, which is part of the geosphere
hope this helped :)
Answer:
solid change directly into a vapor in the process known simply as freezing
Answer:
8.625 grams of a 150 g sample of Thorium-234 would be left after 120.5 days
Explanation:
The nuclear half life represents the time taken for the initial amount of sample to reduce into half of its mass.
We have given that the half life of thorium-234 is 24.1 days. Then it takes 24.1 days for a Thorium-234 sample to reduced to half of its initial amount.
Initial amount of Thorium-234 available as per the question is 150 grams
So now we start with 150 grams of Thorium-234





So after 120.5 days the amount of sample that remains is 8.625g
In simpler way , we can use the below formula to find the sample left

Where
is the initial sample amount
n = the number of half-lives that pass in a given period of time.