Let's hope she didn't watch it without me or i will never be speaking to her again :))
Answer:
The main function of the cell membrane is to protect the cell from the outer environment.
Answer:

one atom of an element = 6.02 \times {10}^{23} atom
The mass of one atom of sulphur = 32g
The mass of one atom of aluminium = 27g
so one atom of aluminium = 6.02 \times {10}^{23}
27g of AL = 6.02 \times {10}^{23} atom
2.70g of AL = X atoms
Then you cross multiply ........
and get the answer
.
Answer and
Explanation
I believe the correct answer would be the last option. When an electrons moves from an excited state to the ground state, it would release energy. An electron in the excited state would mean that it contains high kinetic energy so to move to a lower state some of these energy should be released.