Q: What is the energy change ($$\Delta E) $$when an electron in a hydrogen atom transitions from $$n_i = 5 to$$ $$n_f = 3$$? Use $$R_H = 2.18 \times 10$$^{-18}$$ J.

$$\Delta E = -1.55 \times 10$$^{-19}$$ J

Q: Which equation correctly represents the energy difference for an electron transition in the hydrogen atom?

$$\Delta E = (-2.18 \times 10$$^{-18}$$ \text{ J}) \left( \frac{1}{n_i^2$} - \frac{1}{n_f^2$} \right)$$

Question 1

According to the Bohr model, which statement best describes the behavior of electrons in a hydrogen atom?

Accepted Answer

Electrons exist in specific orbits at fixed distances from the nucleus, and their energy is quantized.

Question 2

What is the energy change ($$\Delta E) $$when an electron in a hydrogen atom transitions from $$n_i = 5 to$$ $$n_f = 3$$? Use $$R_H = 2.18 	imes 10$$^{-18}$$ J.

Accepted Answer

$$\Delta E = -1.55 	imes 10$$^{-19}$$ J

Question 3

Which type of electromagnetic radiation is emitted when an electron drops from $$n = 5 to$$ $$n = 3 in a $$hydrogen atom?

Accepted Answer

Infrared

Question 4

Which equation correctly represents the energy difference for an electron transition in the hydrogen atom?

Accepted Answer

$$\Delta E = (-2.18 	imes 10$$^{-18}$$ 	ext{ J}) \left( \frac{1}{n_i^2$} - \frac{1}{n_f^2$} ight)$$

Question 5

Which quantum number determines the shape of an orbital?

Accepted Answer

Angular momentum quantum number ($$l)$$

Question 6

How many $$d$$ orbitals are present in the $$n = 3$$ shell?

Accepted Answer

5

Question 7

Which statement best describes the Heisenberg uncertainty principle?

Accepted Answer

The more precisely the position of a particle is known, the less precisely its momentum can be known.

Question 8

What is the shape of an $$s$$ orbital?

Accepted Answer

Spherical

Question 9

For $$n = 4$$, how many total orbitals are present in the shell?

Accepted Answer

16

Question 10

Which quantum number describes the three-dimensional orientation of an orbital?

Accepted Answer

Magnetic quantum number ($$m_l)$$

Question 11

According to de Broglie, what is the wavelength ($$\lambda) of a $$particle with mass $$m$$ and velocity $$u$$?

Accepted Answer

$$\lambda = \frac{h}{mu}$$

Question 12

Which of the following is NOT a limitation of the Bohr model?

Accepted Answer

It accurately predicts the spectral lines for all elements.

Question 13

What is the probability interpretation of the wave function ($$\psi) in $$quantum mechanics?

Accepted Answer

The square of the wave function ($$\$$psi^2$$) gives the probability density of finding the electron at a given location.

Question 14

Which set of quantum numbers is valid for a 3p orbital?

Accepted Answer

$$n = 3, l = 1, m_l = 0$$

Question 15

If an electron absorbs a photon and moves from $$n = 1 to$$ $$n = 2$$, what is the sign of $$\Delta E$$?

Accepted Answer

Positive

Question 16

How many possible values of $$m_l$$ are there for $$l = 2$$?

Accepted Answer

5

Question 17

Which orbital type is associated with $$l = 1$$?

Accepted Answer

p

Question 18

A hydrogen atom emits a photon as its electron transitions from $$n = 4 to$$ $$n = 2. $$Which formula would you use to calculate the wavelength ($$\lambda) of $$the emitted photon?

Accepted Answer

$$\lambda = \frac{h c}{\Delta E}$$

Question 19

Which statement best describes the difference between Bohr's model and the quantum mechanical model?

Accepted Answer

Bohr's model describes electrons in fixed orbits, while quantum mechanics describes electrons in orbitals defined by probability distributions.

Electronic Structure of Atoms: The Bohr Model and Quantum Mechanics

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