What is a main component of steel

A modern compact fluorescent lamp contains 1.4 mg of mercury (Hg). If each mercury atom in the lamp were to emit a single photon

Reika [66]

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:

$n=\frac{m}{M_m}$

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

$n=\frac{0.0014 g}{200.6 g/mol}=7.0\cdot 10^{-6} mol$

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

$N=n N_A$

where

n is the number of moles

$N_A=6.022\cdot 10^{23} mol^{-1}$ is the Avogadro number

Substituting,

$N=(7.0\cdot 10^{-6} mol)(6.022\cdot 10^{23} mol^{-1})=4.22\cdot 10^{18}$ atoms

The energy emitted by each atom (the energy of one photon) is

$E_1 = \frac{hc}{\lambda}$

where

h is the Planck constant

c is the speed of light

$\lambda=508 nm=5.08\cdot 10^{-7}nm$ is the wavelength

Substituting,

$E_1 = \frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{5.08\cdot 10^{-7} m}=3.92\cdot 10^{-19} J$

And so, the total energy emitted by the sample is

$E=nE_1 = (4.22\cdot 10^{18} )(3.92\cdot 10^{-19}J)=1.64 J$

4 0

3 years ago

What type of energy does a pv cell create ?

Alex_Xolod [135]

Answer: Solar Photovoltaic (PV) cells generate electricity by absorbing sunlight and using that light energy to create an electrical current. There are many PV cells within a single solar panel, and the current created by all of the cells together adds up to enough electricity to help power your school, home and businesses.

--Cited from Solar Schools

6 0

2 years ago

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What is the public storm warning signal that carries winds of 30 to 60 km/hr and can cause no damage to very light damage

Shkiper50 [21]

Answer:

I know u need this

Explanation:

You gave me the runaround

I really hate the runaround

You really got me paranoid

I always keep a gun around

You always give me butterflies

When you come around

7 0

2 years ago

A pendulum has 576 J of potential energy at the highest point of its swing. How much kinetic energy will it have at the bottom o

Natalka [10]

Ideally, 576 J because energy is conserved.
In the real world, a tiny tiny tiny tiny bit less than 576 J ,
because we live in a world with friction and air resistance.

3 0

3 years ago

Free pointzzzzz for everyoneeeee

PolarNik [594]

Answer:

Thank you so much.

Explanation:

Please give me brainliest :) I will greatly appreciate it :D

7 0

2 years ago

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