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:
They're going to increase the total resistance as 
Explanation:
If the resistors are in parallel, the potential difference is the same for each resistor. But the total current is the sum of the currents that pass through each of the resistors. Then

where

but
for 
so

where

Answer:
α= 1.3 10-5 ºC⁻¹
Explanation:
La dilatación termica de los cuerpos esta dada por la relación
ΔL = L₀ α ( T -T₀)
en este caso nos piden el coeficiente de dilatación térmica
α =DL/L₀ DT
calculemos
α = ( 100,13 -100)/[100 (100 – 0)]
α = 1,3 10-5 ºC⁻¹
Traduction
The thermal expansion of bodies is given by the relationship
ΔL = L₀ α (T -T₀)
in this case they ask us for the coefficient of thermal expansion
α = ΔL / L₀ ΔT
let's calculate
α = (100,13 -100) / [100 (100 - 0)]
α= 1.3 10-5 ºC⁻¹
ANSWER and EXPLANATION
We want to identify if there will be an electric field and a magnetic field around the two sticks electrified by charges of opposite signs.
An electric field is a physical field that surrounds electrically charged particles and exerts a force on other charged particles in the surrounding.
This implies that the presence of electric charges on both sticks generates electric fields on them. Since the two charges are opposite, the electric force acting on them will be attractive.
Hence, there is an electric field.
A stationary charged object produces an electric field, as explained above, but will only produce a magnetic field if there is a motion of the object.
Hence, except the two sticks are caused to move, there will be no magnetic field around them.