I think the best one is B
Answer: The energy of a mole of photon associated with this frequency is 
Explanation:
The energy and frequency are related by :

E = energy of photon
N = number of moles = 1
h = planks constant = 
= frequency = 

The energy of a mole of photon associated with this frequency is 
66.2 kg 1) 25 kg H X (1 mol / 2.016) X (16.043 / 1 mol)= 66.2kg I am sorry if this is not what you looking for my friend
Answer:
4
Explanation:
If I remember correctly, the atomic # will always be the same as the # of electrons
Im assuming, if you find rare earth elements, it is important to the technological world bc you can make more products more better, and even invent new and more modern things.