Q: A photon has a frequency of $6.0 \times 10^{14}\ \mathrm{Hz}$. What is its energy in joules? (Planck's constant $h = 6.63 \times 10^{-34}\ \mathrm{J \cdot s}$)

$3.98 \times 10^{-19}\ \mathrm{J}$

Q: What is the de Broglie wavelength of an electron (mass $9.11 \times 10^{-31}\ \mathrm{kg}$) moving at $2.0 \times 10^6\ \mathrm{m/s}$? ($h = 6.63 \times 10^{-34}\ \mathrm{J \cdot s}$)

$3.6 \times 10^{-10}\ \mathrm{m}$

Question 1

Which of the following correctly expresses the relationship between the speed of light $c$, wavelength $\lambda$, and frequency $
u$ of electromagnetic radiation?

Accepted Answer

$c = \lambda 
u$

Question 2

A photon has a frequency of $6.0 	imes 10^{14}\ \mathrm{Hz}$. What is its energy in joules? (Planck's constant $h = 6.63 	imes 10^{-34}\ \mathrm{J \cdot s}$)

Accepted Answer

$3.98 	imes 10^{-19}\ \mathrm{J}$

Question 3

According to Planck's theory, the energy of electromagnetic radiation is quantized. Which equation represents the energy of a quantum of radiation?

Accepted Answer

$E = h 
u$

Question 4

In the photoelectric effect, what determines whether electrons are ejected from a metal surface when light shines on it?

Accepted Answer

The frequency of the incident light must be above a threshold value.

Question 5

Which of the following statements about the Bohr model of the hydrogen atom is correct?

Accepted Answer

Electrons move in fixed orbits with quantized energies.

Question 6

What is the de Broglie wavelength of an electron (mass $9.11 	imes 10^{-31}\ \mathrm{kg}$) moving at $2.0 	imes 10^6\ \mathrm{m/s}$? ($h = 6.63 	imes 10^{-34}\ \mathrm{J \cdot s}$)

Accepted Answer

$3.6 	imes 10^{-10}\ \mathrm{m}$

Question 7

Heisenberg's uncertainty principle states that:

Accepted Answer

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

Question 8

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

Accepted Answer

$n=2,\ l=2,\ m_l=0,\ m_s=+\frac{1}{2}$

Question 9

How many different atomic orbitals are possible for the principal quantum number $n=3$?

Accepted Answer

9

Question 10

Which of the following best describes a $p$ orbital?

Accepted Answer

It has a dumbbell shape and there are three $p$ orbitals per energy level (for $n \geq 2$).

Question 11

According to the Pauli exclusion principle, which statement is true?

Accepted Answer

No two electrons in the same atom can have the same set of four quantum numbers.

Question 12

Which of the following electron configurations represents a diamagnetic atom?

Accepted Answer

All electrons are paired in their orbitals.

Question 13

Which principle explains the order in which electrons fill atomic orbitals?

Accepted Answer

Aufbau principle

Question 14

A transition metal typically forms ions by losing electrons from which orbitals first?

Accepted Answer

The $s$ orbital of the highest principal quantum number

Question 15

How many electrons can occupy all the orbitals with $n=2$ in a multi-electron atom?

Accepted Answer

8

Question 16

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Azimuthal quantum number $l$

Question 17

If an atom has the electron configuration $1s^2 2s^2 2p^6 3s^2 3p^6 4s^1$, what is the element and what is its most common ion?

Accepted Answer

Potassium, $K^+$

Question 18

Which of the following statements about the energy of orbitals in a multi-electron atom is correct?

Accepted Answer

For a given $n$, $E_{s} < E_{p} < E_{d} < E_{f}$

Question 19

A sodium lamp emits yellow light with a wavelength of $589\ \mathrm{nm}$. What is the frequency of this light? ($c = 3.00 	imes 10^8\ \mathrm{m/s}$)

Accepted Answer

$5.09 	imes 10^{14}\ \mathrm{Hz}$

La structure électronique des atomes : Concepts de la mécanique quantique et configuration électronique

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