1. 
First of all, let's convert the energy of the absorbed photon into Joules:
The energy of the photon can be rewritten as:
where
h is the Planck constant
c is the speed of light
is the wavelength of the photon
Re-arranging the formula, we can solve to find the wavelength of the absorbed photon:
2. 1.24 eV
In this case, when the electron jumps from the n=4 level to the n=3 level, emits a photon with wavelength
So the energy of the emitted photon is given by the formula used previously:
and using
we find
converting into electronvolts,
EDIT: an issue in Brainly does not allow me to add the last 2 parts of the solution - I have added them as an attachment to this post, check the figure in attachment.
Answer:
1.308 * 10^(-5) m
Explanation:
We apply the condition for a single slit experiment:
y = (λ * D) / a
Where y = half width of fringe
λ = wavelength of light
D = distance of slit from screen
a = width of slit
We need to find a, so we make a the subject of formula:
a = (λ * D) / y
From the question:
λ = 550 nm = 550 * 10^(-9) m
D = 0.63 m
y = 0.053 / 2 = 0.0265 m
Therefore:
a = (550 * 10^(-9) * 0.63) / 0.0265
a = 1.308 * 10^(-5) m
The width of the slit is 1.308 * 10^(-5) m
Waves transfer energy not matter. so simply put, the water doesn't move. it's just being used as a road that energy uses to get from point a to b. it's easier to think of some thing on the water rather than the water it self. like a cork floating on the surface. when a wave passes through the cork. the cork goes up to the peak of the wave and then down to the trough of the wave and then back at equilibrium. it only moved up and down since it was following the wave pattern. if the waves transfered matter as well as energy then the cork would begin to get pushed by the wave and move towards the direction of travel
For the answer to the question above,
<span>Q = amount of heat (kJ) </span>
<span>cp = specific heat capacity (kJ/kg.K) = 4.187 kJ/kgK </span>
<span>m = mass (kg) </span>
<span>dT = temperature difference between hot and cold side (K). Note: dt in °C = dt in Kelvin </span>
<span>Q = 100kg * (4.187 kJ/kgK) * 15 K </span>
<span>Q = 6,280.5 KJ = 6,280,500 J = 1,501,075.5 cal</span>
This would prove that gold is an <em>element</em>. No matter how far down you
examine it, you never find any particles of anything except gold.
An example of a different case is salt.
-- Imagine you had a block of salt and decided to cut it in half.
-- If you repeated this process, then eventually, at some point, you'd have
a tiny particle of salt in front of you, just like before. BUT ...
-- Just as you were getting ready to cut this one in half, you'd notice that this
particle of salt is different. It's one atom of sodium stuck to one atom of chlorine,
and if you cut it in half, you would not have ANY salt. <span />
This would prove that salt is a <em><u>compound</u></em>, made of atoms of two or more elements.
