Answer:
A. 1.64 J
Explanation:
First of all, we need to find how many moles correspond to 1.4 mg of mercury. We have:

where
n is the number of moles
m = 1.4 mg = 0.0014 g is the mass of mercury
Mm = 200.6 g/mol is the molar mass of mercury
Substituting, we find

Now we have to find the number of atoms contained in this sample of mercury, which is given by:

where
n is the number of moles
is the Avogadro number
Substituting,
atoms
The energy emitted by each atom (the energy of one photon) is

where
h is the Planck constant
c is the speed of light
is the wavelength
Substituting,

And so, the total energy emitted by the sample is

Answer:
I think c is the answer but I have a little concern on d too
Answer:
It would be hard to test scientifically since it's subjective and can only be proven true if you conducted some experimentations and observations.
Answer:
Mixtures are materials that contain two or more chemical substances dispersed among each other (mixed together). If no chemical reaction occurs when two materials are mixed, they form a mixture. The chemical properties of the components don't change.
Explanation: