Answer:
C. Methane
Explanation:
Hopefully this isnt too late!
Answer:
No empty orbitals but five unpaired electrons.
Explanation:
Hello there!
In this case, when going over the empty orbitals in valence energy levels, it is required to develop the electron configuration in order to appropriately describe the element. In such a way, for the element whose atomic number is 25 because it equals the number of electrons, we obtain:

It means that the d orbital is half filled which means that it does not have any empty orbital wherein two electrons are contained per orbital. Moreover, we can find 5 unpaired electrons according to:
↑ ↑ ↑ ↑ ↑
Which is the orbital notation.
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Answer:
used in irrigation to transfer water over a barrier
The last option, "Energy that flows from a hot mug of tea to a cold hand." Hope this helps!
(This is because heat is the transfer of energy that you can well, feel. In simple terms. For this question and other like it you can do process of elimination because the only one that involves heat, is the last option.)