Yes everything looks good to me
Answer:

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

Hope this helps you
Answer:
I believe the answer would be C4H9O2.
When an atom gains an electron it becomes a negatively charged ion. When an atom looses an electron it becomes positively charged because the number of positively charged protons.
Hope this helps