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ExtremeBDS [4]
3 years ago
11

An electron in the hydrogen atom makes a transition from an energy state of principal quantum number ni to the n = 2 state. If t

he photon emitted has a wavelength of 657 nm, what is the value of ni?
Chemistry
1 answer:
topjm [15]3 years ago
7 0

Answer:

\boxed{3}

Explanation:

The Rydberg equation gives the wavelength λ for the transitions:

\dfrac{1}{\lambda} = R \left ( \dfrac{1}{n_{i}^{2}} - \dfrac{1}{n_{f}^{2}} \right )

where

R= the Rydberg constant (1.0974 ×10⁷ m⁻¹) and

\text{$n_{i}$ and $n_{f}$ are the numbers of the energy levels}

Data:

n_{f} = 2

λ = 657 nm

Calculation:  

\begin{array}{rcl}\dfrac{1}{657 \times 10^{-9}} & = & 1.0974 \times 10^{7}\left ( \dfrac{1}{2^{2}} - \dfrac{1}{n_{f}^{2}} \right )\\\\1.522 \times 10^{6} &= &1.0974\times10^{7}\left(\dfrac{1}{4} - \dfrac{1}{n_{f}^{2}} \right )\\\\0.1387 & = &\dfrac{1}{4} - \dfrac{1}{n_{f}^{2}} \\\\-0.1113 & = & -\dfrac{1}{n_{f}^{2}} \\\\n_{f}^{2} & = & \dfrac{1}{0.1113}\\\\n_{f}^{2} & = & 8.98\\n_{f} & = & 2.997 \approx \mathbf{3}\\\end{array}\\\text{The value of $n_{i}$ is }\boxed{\mathbf{3}}

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Katen [24]

Answer:

Interphase, mitosis, and cytokenesis

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3 years ago
According to Hund's Rule, if you were filling the three orbitals at the 2p energy level, you would first put an electron in the
GenaCL600 [577]

Answer:

True.

Explanation:

The Hund's Rule states that all orbitals must be singled occupied before any orbital is doubly occupied, and all the electrons at the singly occupied orbitals have the same spin number. By doing that, the electrons filled the lowest energy orbitals first.

The 2p level has 3 orbitals: 2px, 2py, and 2pz. So, when filling it, first put an electron in the 2px, then in the 2py, then and the 2pz (all with the same spin). After that, the remains electrons can be paired up.

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3 years ago
What is the final concentration when 5 ml of a 2.5M copper sulphate solution is diluted to 750 ml?
Firdavs [7]

Answer: The final concentration when 5 ml of a 2.5M copper sulphate solution is diluted to 750 ml is 0.017 M

Explanation:

According to the dilution law,

M_1V_1=M_2V_2

where,  

M_1 = molarity of stock CuSO_4 solution = 2.5 M

V_1 = volume of stock CuSO_4solution = 5 ml  

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V_1 = volume of diluted CuSO_4 solution = 750 ml

Putting in the values we get:

2.5\times 5=M_2\times 750

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Therefore the final concentration when 5 ml of a 2.5M copper sulphate solution is diluted to 750 ml is 0.017 M

6 0
3 years ago
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Answer:

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Explanation:

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2 years ago
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Answer: A closed system, because energy can enter or leave the container, but the water molecules cannot

Explanation:

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Isolated system:In this type system exchange of both energy and matter are restricted to move outside the boundaries of system.

According to question, the system given is a closed system because energy is transferred from the burner to glass flask and from the glass flask to the water (matter). But water molecules are only getting condensed on the inside surface of the flask that is exchange of matter beyond the boundaries of the system is restricted. Hence, closed system ,A closed system, because energy can enter or leave the container, but the water molecules cannot.

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3 years ago
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