The gas is NH₃.
H₂ doesn't dissolve readily in water, SO₂ gives an acidic solution in water.
The solid residue is Fe(OH)₂.
FeSO₄ and Na₂SO₄ are soluble in water.
The answer is C.
Here you are looking on the Free Body diagram of a net force of 0N in both the x and y-directions. the only ones that has that condition met is A and C.
The decreasing order of wavelengths of the photons emitted or absorbed by the H atom is : b → c → a → d
Rydberg's formula :
,
where λ is the wavelength of the photon emitted or absorbed from an H atom electron transition from 
to 
and 
= 109677 is the Rydberg Constant. Here and represents the transitions.
(a) =2 to = infinity
= 109677/4 [since 1/infinity = 0] Therefore, 
= 4 / 109677 = 0.00003647 m
(b) =4 to = 20
= 6580.62
Therefore, = 1 / 6580.62 = 0.000152 m
(c) =3 to = 10
= 11089.56
Therefore, = 1 / 11089.56 = 0.00009 m
(d) =2 to = 1
= - 82257.75
Therefore, = 1 /82257.75 = - 0.0000121 m
[Even though there is a negative sign, the magnitude is only considered because the sign denotes that energy is emitted.]
So the decreasing order of wavelength of the photon absorbed or emitted is b → c → a → d.
Learn more about the Rydberg's formula athttps://brainly.com/question/14649374
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<span>The student should
follow following steps to make 1 L of </span>2.0 M CaCl₂.<span>
<span>
1. First he should
calculate the number of moles of 2.0 M CaCl</span></span>₂ in 1 L solution.<span>
</span>Molarity of the solution = 2.0 M<span>
Volume of solution which should be prepared = 1 L
Molarity =
number of moles / volume of the solution
Hence, number of moles in 1 L = 2 mol
2. Find
out the mass of dry CaCl</span>₂ in 2 moles.<span>
moles =
mass / molar mass
Moles of CaCl₂ =
2 mol</span><span>
Molar mass of CaCl₂ = </span><span>110.98 g/mol
Hence, mass of CaCl</span>₂ = 2 mol x <span>110.98 g/mol
= 221.96
g
3. Weigh the mass
accurately
4. Then take a cleaned and dry1 L volumetric flask and place a funnel top of it. Then carefully add the salt into the volumetric flask and
finally wash the funnel and watch glass
with de-ionized water. That water also should be added into the volumetric
flask.
5. Then add some
de-ionized water into
the volumetric flask and swirl well until all salt are
dissolved.
<span>6. Then top up to
mark of the volumetric flask carefully.
</span></span>
7. As the final step prepared solution should be labelled.
Answer: The density of the material is 2.66 g/mL and it is likely this is made of Aluminum
Explanation:
The first step to know the material of the chunk of metal is to calculate its density. The general formula for density is P (density) = 
. Moreover, in this case, it is known the mass is 37.28 g, but the volume is not directly provided. However, we know the water in the graduated cylinder had a volume of 20.0 mL and this increased to 34.0 mL when the chunk of metal is added, this means the volume of the metal is 14 mL (34.0 mL - 20.0 mL = 14 mL). Now let's calculate the density:
This means the density of this metal is 2.66 g/mL, which can be rounded as 2. 7 g/mL, and according to the chart, this is the density of aluminum. Therefore, this material of this chunk is aluminum.
