Question 1

An atomic orbital ________.

Accepted Answer

An atomic orbital is a region of space where there is a high probability of finding an electron. This region of space can take the shape of a sphere, dumbbell, or other complex shapes depending on the type of orbital. It can hold up to two electrons (in the case of s orbitals) or a maximum of eight electrons (in the case of p orbitals).

Question 2

An electron de-excites from the fourth quantum level to the third and then directly to the first. Two frequencies of light are emitted. How do their combined energies compare to the energy of the single frequency that would be emitted by de-excitation from the fourth level directly to the first level?

Accepted Answer

The combined energies of the two frequencies emitted during the stepwise de-excitation (from the fourth to the third level and then from the third to the first level) are equal to the energy of the single frequency that would be emitted if the electron de-excited directly from the fourth to the first level. This is because energy levels in atoms are quantized and the energy difference between specific levels is fixed, so the total energy released in transitions is conserved regardless of the path taken.

Question 3

The energy level diagram ranks orbitals by their ________.

Accepted Answer

An energy level diagram shows the relative energy of each orbital, with higher energy orbitals being farther from the nucleus. Therefore, the orbitals are ranked by their average distance from the nucleus.

Question 4

How does the wave model of electrons orbiting the nucleus account for the fact that the electrons can have only discrete energy values?

Accepted Answer

When an electron wave is confined, it can interfere and reinforce only at particular frequencies, leading to discrete energy values. This is known as quantization and is a fundamental aspect of the wave model of electrons orbiting the nucleus.

Question 5

How might the spectrum of an atom appear if its electrons were not restricted to particular energy levels?

Accepted Answer

The restriction of electrons to specific energy levels leads to the production of distinct spectral lines. Without this restriction, the electrons could emit radiation at any frequency, resulting in a broad spectrum of colors.

Question 6

How can a hydrogen atom, which has only one electron, have so many spectral lines?

Accepted Answer

The spectral lines of hydrogen are the result of the electron transitioning between different energy levels. Hydrogen has several energy levels available for the electron to occupy, and each transition between those levels corresponds to a different wavelength of light emission or absorption.

Question 7

What is a probability cloud?

Accepted Answer

A probability cloud is a three-dimensional map that shows the likelihood or probability of finding something within a given area. This is commonly used in quantum mechanics to represent the probability of finding an electron in a certain region of an atom.

Question 8

Suppose that a certain atom possesses only four distinct energy levels. Assuming that all transitions between levels are possible, how many spectral lines will this atom exhibit?

Accepted Answer

The number of spectral lines that an atom with n energy levels can have is given by the formula n(n-1)/2. Therefore, for an atom with 4 energy levels, there will be 4(4-1)/2 = 6 spectral lines.

Question 9

An atom absorbs or emits only particular frequencies of light. White light bends into a glass prism and separates into a rainbow of colors. In which of these two scenarios does the electromagnetic radiation behave as a wave? As a particle?

Accepted Answer

Absorption of light by atoms demonstrates particle behavior because it involves photons (particles of light) being absorbed by electrons in the atom, which can then jump to higher energy levels. The bending of light as it passes through a prism (refraction) demonstrates wave behavior, as the different wavelengths (colors) of light are bent at different angles due to their different speeds in the glass, a phenomenon best explained by the wave model of light.

Question 10

Which color of light comes from the higher energy transition, red or blue?

Accepted Answer

According to the electromagnetic spectrum, blue light has a higher frequency than red light. This means that blue light corresponds to a higher energy level transition than red light. Therefore, option B is the correct answer.

Question 11

Each atomic orbital can hold ________.

Accepted Answer

According to the Pauli exclusion principle, each atomic orbital can hold a maximum of 2 electrons, each with opposite spins.

Question 12

What is the relationship between the light emitted by an atom and the energies of the electrons in the atom?

Accepted Answer

The energy of an electron in an atom is directly proportional to the frequency of light emitted when that electron goes from a higher energy level to a lower one. This is known as the Bohr model of the atom. Therefore, the greater the frequency of a photon of light, the greater the energy packed into that photon.

Question 13

In some instances electromagnetic radiation behaves like a wave. In other instances electromagnetic radiation behaves more like a particle. Which behavior more accurately describes the true nature of electromagnetic radiation?

Accepted Answer

Electromagnetic radiation has both wave-like and particle-like properties, which is known as wave-particle duality. Electromagnetic radiation can exhibit wave behavior such as interference and diffraction, and it can also exhibit particle behavior such as absorption and emission of energy in discrete packets (photons). The behavior of electromagnetic radiation depends on the circumstance and the way it is being observed or measured.

Question 14

The electron configuration of any neutral group 1 element always ends with ________.

Accepted Answer

Group 1 elements (alkali metals) have their outermost electron in an s orbital, and since they have one electron in their outermost shell, the correct notation ends with s^1, which corresponds to choice A when decoded from the provided format.

Question 15

Which of the following statements about electrons is true?

Accepted Answer

All of the above statements are true. Electrons have a negative charge, they are particles, and they can behave like waves in certain situations. In addition, electrons in atoms can be excited by light energy, which can cause them to move to higher energy levels or even be ejected from the atom altogether.

Question 16

What property of an electron makes it possible to use electron microscopes?

Accepted Answer

The shorter wavelengths of electrons make it possible to achieve higher resolution in electron microscopes compared to optical microscopes. This is due to the fact that the resolution of a microscope is proportional to the wavelength of the radiation used. As electrons have much shorter wavelengths than visible light, they can be used to visualize much smaller objects and details.

Question 17

How might you distinguish a sodium-vapor street lamp from a mercury-vapor street lamp?

Accepted Answer

By looking at the street lamps through a spectroscope, one can match their spectral patterns to their respective atomic spectra. Sodium-vapor lamps have a characteristic yellow-orange glow, while mercury-vapor lamps have a bluish-green tint. This method provides a clear and accurate identification.

Question 18

Light is emitted as an electron transitions from a higher energy state to a lower energy state. How long does it take for the actual transition to take place?

Accepted Answer

The transition between energy states occurs instantaneously and therefore takes no time at all. However, the emission of light may take a measurable amount of time depending on the medium through which it travels.

Question 19

Which of the following might best explain the reason why electrons are restricted to certain energy levels in an atom?

Accepted Answer

Electrons behave like restricted waves and are self-reinforcing, which leads to quantized energy levels in an atom. This is known as wave-particle duality and is a fundamental concept in quantum mechanics.

Question 20

Consider the various frequencies of the three photons emitted from the following three individual electron transitions in the figure below: n=3 to n=2; n=2 to n=1; n=3 to n=1. These transitions would produce three spectral lines in a spectroscope. If the energy spacing between the levels were equal, would this affect the number of spectral lines?

Accepted Answer

The answer of Consider the various frequencies of the three...

Quiz 4: Subatomic Particles