Question 1

Which equation expresses the de Broglie wavelength of a particle with mass $$m$$ and velocity $$v$$?

Accepted Answer

$$\lambda = \dfrac{h}{mv}$$

Question 2

Given an electron ($$m = 9.11 	imes 10$$^{-31}$$ kg) moving at 3.00$$ 	imes $$10^6 m/s$$, what is its de Broglie wavelength? ($$h = 6.63 	imes 10$$^{-34}$$ J·s)

Accepted Answer

$$2.43 	imes 10$$^{-10}$$\ m$

Question 3

A baseball ($$m = 0.145 kg) is $$thrown at $$26.8 m/s. $$What is its de Broglie wavelength? ($$h = 6.63 	imes 10$$^{-34}$$ J·s)

Accepted Answer

$$1.71 	imes 10$$^{-34}$$\ m$

Question 4

If a proton is approximately 2000 times heavier than an electron, and both have the same de Broglie wavelength, how do their velocities compare?

Accepted Answer

The electron's velocity is about 2000 times greater than the proton's.

Question 5

Which of the following best describes the Heisenberg Uncertainty Principle?

Accepted Answer

It is impossible to know both the exact position and momentum of a particle simultaneously.

Question 6

Which equation represents the Heisenberg Uncertainty Principle for position ($$\Delta x) $$and momentum ($$\Delta p$$)?

Accepted Answer

$$\Delta x \cdot \Delta p \geq \dfrac{h}{4\pi}$$

Question 7

Which quantum number primarily determines the energy and size of an atomic orbital?

Accepted Answer

Principal quantum number ($$n)$$

Question 8

How many orbitals are present in a $$d$$ subshell?

Accepted Answer

5

Question 9

Which set of quantum numbers is NOT permitted for an electron in an atom?

Accepted Answer

$$n=4,\ \ell=4,\ m_\ell=0,\ m_s=+\frac{1}{2}$$

Question 10

What is the maximum number of orbitals in the $$n=3$$ shell?

Accepted Answer

9

Question 11

Which quantum number describes the orientation of an orbital in space?

Accepted Answer

Magnetic quantum number ($$m_\ell)$$

Question 12

For the $$n=2$$ shell, how many $$p$$ orbitals are present?

Accepted Answer

3

Question 13

Which subshell type is present in the $$n=4$$ shell but not in the $$n=3$$ shell?

Accepted Answer

$$f$$

Question 14

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

Accepted Answer

Spherical

Question 15

Which quantum number can have values of $$+\frac{1}{2} or$$ $$-\frac{1}{2}$$?

Accepted Answer

Spin quantum number ($$m_s)$$

Question 16

If the probability density for an electron in a hydrogen atom is highest at $$r = 50 pm$$, what does this indicate?

Accepted Answer

The most likely distance to find the electron is 50 pm from the nucleus.

Question 17

Which of the following statements about atomic orbitals is correct?

Accepted Answer

An atomic orbital describes a region of space with a high probability of finding an electron.

Question 18

How many possible values of $$m_\ell$$ are there for a $$f$$ subshell?

Accepted Answer

7

Question 19

Which quantum number distinguishes orbitals of a given energy and shape but with different orientations?

Accepted Answer

Magnetic quantum number ($$m_\ell)$$

Question 20

Which of the following is a consequence of quantum mechanics for electrons in atoms?

Accepted Answer

We can only make statistical statements about where an electron is likely to be found.

Quantum Mechanics and the Wave Nature of Matter - Chap. 8 P2

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