Q: According to the de Broglie hypothesis, what is the wavelength $$\lambda of an $$electron (mass $$9.11 \times 10$$^{-31}$$ kg) moving at 1.00$$\%$$ of the speed of light (c = 3.00$$ \times $$10^8 m/s$$)? Use $$h = 6.63 \times 10$$^{-34}$$ J·s.

$$\lambda = 7.27 \times 10$$^{-10}$$ m

Q: A baseball (mass = 0.145 kg) is thrown at 105 mph ($$47.0 m/s). $$What is its de Broglie wavelength? ($$h = 6.63 \times 10$$^{-34}$$ J·s)

$$\lambda = 9.70 \times 10$$^{-34}$$ m

Question 1

Which of the following best describes the result of the double-slit experiment when electrons are fired one at a time through two slits and no measurement is made to determine which slit the electron passes through?

Accepted Answer

An interference pattern of alternating bright and dark bands, characteristic of wave behavior.

Question 2

According to the de Broglie hypothesis, what is the wavelength $$\lambda of an $$electron (mass $$9.11 	imes 10$$^{-31}$$ kg) moving at 1.00$$\%$$ of the speed of light (c = 3.00$$ 	imes $$10^8 m/s$$)? Use $$h = 6.63 	imes 10$$^{-34}$$ J·s.

Accepted Answer

$$\lambda = 7.27 	imes 10$$^{-10}$$ m

Question 3

Which of the following sets of quantum numbers is NOT allowed for an electron in an atom?

Accepted Answer

$$n = 4, \ l = 4, \ m_l = 0$$

Question 4

A baseball (mass = 0.145 kg) is thrown at 105 mph ($$47.0 m/s). $$What is its de Broglie wavelength? ($$h = 6.63 	imes 10$$^{-34}$$ J·s)

Accepted Answer

$$\lambda = 9.70 	imes 10$$^{-34}$$ m

Question 5

Which quantum number determines the overall energy of an electron in a hydrogen atom?

Accepted Answer

Principal quantum number ($$n)$$

Question 6

How many orbitals are present in the $$n = 4$$ shell of an atom?

Accepted Answer

16

Question 7

Which of the following best explains why macroscopic objects like baseballs do not exhibit observable quantum interference patterns in a double-slit experiment?

Accepted Answer

Their de Broglie wavelengths are too small to produce observable interference.

Question 8

For the quantum numbers $$n = 5$$, $$l = 3$$, $$m_l = -2$$, in which subshell is the electron found?

Accepted Answer

5f

Question 9

What is the total number of orbitals possible for $$n = 3$$?

Accepted Answer

9

Question 10

Which quantum number(s) determine the shape of an atomic orbital?

Accepted Answer

Azimuthal quantum number ($$l) $$only

Question 11

In a double-slit experiment, what happens to the interference pattern if a measurement is made to determine which slit each electron passes through?

Accepted Answer

The interference pattern disappears and two single-slit patterns are observed.

Question 12

Which of the following statements about the magnetic quantum number ($$m_l) is $$correct?

Accepted Answer

$$m_l$$ determines the orientation of the orbital in space.

Question 13

What is the energy of an electron in the $$n = 2$$ level of a hydrogen atom, given $$E_n = -2.18 	imes 10$$^{-18}$$ \ \mathrm{J} 	imes \frac{1}{n^2$}$$?

Accepted Answer

$$-1.09 	imes 10$$^{-18}$$ J

Question 14

Which of the following best describes the difference between the interference pattern observed with water waves and with bullets in a double-slit experiment?

Accepted Answer

Water waves produce an interference pattern, while bullets produce two distinct bands.

Question 15

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

Accepted Answer

5

Question 16

Which of the following is a correct set of quantum numbers for a 3p orbital?

Accepted Answer

$$n = 3, \ l = 1, \ m_l = +1$$

Question 17

What is the total number of orbitals in the $$n = 5$$ shell?

Accepted Answer

25

Question 18

Which quantum number(s) determine the number of nodal planes in an orbital?

Accepted Answer

Azimuthal quantum number ($$l) $$only

Question 19

If an electron is described by the quantum numbers $$n = 4$$, $$l = 0$$, $$m_l = 0$$, in which orbital is it located?

Accepted Answer

4s

Quantum Behavior and Models in General Chemistry

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