Answer:I believe that the answer is c
Explanation: photosynthesis gives us oxygen to breath therefore it is helpful to humans
A). 4
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Answer:
<h3>The answer is option A</h3>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula

where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have

We have the final answer as
<h3>2.99 moles</h3>
Hope this helps you
Answer:
Chemical formula of Oxygen is O2.
We know ,
1 mole of a substance contains 6.022×10^23, Avogadro’s Constat.
Here, Molar mass of O = 16u
And molar mass of O2 = 32u
And 32g of O2 = 1 mole of O2
It means that,
32g of O2 = 6.022×10^23 molecules