Answer:
the second one I think...
In the first shell there is 2 electrons and on the second shell there is 4 elections.
The first diagram is showing carboxylic acid because carboxyl contains a Carbon atom as the central atom bonded with OH group, a double bonded Oxygen, hydrogen ofc, and a lone R group.
2. It is ester group
3. Correct its ether
4. It's the exact diagram for ethyl alcohol, so correct
WOOT WOOOT