Answer:
electrical energy sometimes.
Explanation:
125.0m
300 degree Fahrenheit
A "heating curve" is a graph that shows the temperature of the substance
against the amount of heat you put into it.
For most of the graph, as you'd expect, the temperature goes up as you
add heat, and it goes down as you take heat away. BUT ... While the
substance is changing state, its temperature doesn't change even though
you're putting heat in or taking heat out.
So that part of the graph is a horizontal line.
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
