Question 1

During a dust storm the Sun often appears to redden. This means that the particles of dust:

Accepted Answer

The red color of the Sun during a dust storm is due to the scattering of the shorter wavelength blue light by the small particles of dust in the atmosphere. Since the blue light is scattered more readily than the red light, the remaining light that reaches our eyes appears more red than normal. This indicates that the particles of dust are smaller than the wavelengths of visible light.

Question 2

You are looking at a glowing field of hot lava from a satellite high above Earth's atmosphere. Hot lava emits most of its radiation in the infrared, and Earth's atmosphere is not completely transparent to infrared. What kind of spectrum will you see?

Accepted Answer

An absorption spectrum would be observed since Earth's atmosphere is not completely transparent to infrared radiation emitted by the hot lava. This means that certain wavelengths of the infrared radiation would be absorbed by the atmosphere, resulting in dips or gaps in the spectrum.

Question 3

The overall diameter of a typical atom is about:

Accepted Answer

The overall diameter of a typical atom is about 10^-10 meters (or 0.1 nm). Option D is the only one that lists this value.

Question 4

The typical size of an atom is:

Accepted Answer

The typical size of an atom is on the order of 10^-10 meters, which is also known as an angstrom.

Question 5

The mass of a proton is:

Accepted Answer

The mass of a proton is almost 2000 times greater than that of an electron.

Question 6

The majority of the naturally occurring elements in the periodic table that decay radioactively are:

Accepted Answer

At the high-mass end of the periodic table, the atomic nuclei are very large and unstable. This makes it more likely for the elements to decay through radioactivity. Therefore, the majority of the naturally occurring elements that decay radioactively are found at the high-mass end of the periodic table.

Question 7

According to the arrangement of elements in the periodic table, which of the following elements would be expected to have chemical properties most similar to those of nitrogen, N, whose atomic number is 7?
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Accepted Answer

Nitrogen (N) is in Group 15 of the periodic table, also known as the nitrogen group. The elements in this group have similar electronic configurations, with five electrons in their outermost shells. Phosphorus (P) is also in Group 15, so it would be expected to have chemical properties most similar to those of nitrogen. Oxygen (O) is in Group 16 and has six electrons in its outermost shell, so it would not have similar chemical properties. Chlorine (Cl) is in Group 17 and has seven electrons in its outermost shell, so it would also not have similar chemical properties. Carbon (C) is in Group 14 and has four electrons in its outermost shell, so it would have even less similar chemical properties to nitrogen than oxygen or chlorine.

Question 8

Isotopes of a particular element in the periodic table have which nuclear property in common?

Accepted Answer

Isotopes of a particular element have the same number of protons (which determines their atomic number) but different numbers of neutrons. This results in isotopes having the same chemical properties but slightly different physical properties.

Question 9

How many neutrons are there in the nucleus of the isotope ¹⁸O of oxygen?

Accepted Answer

The answer of How many neutrons are there in the...

Question 10

How do the spectra of the two isotopes ¹H and ²H compare?

Accepted Answer

Isotopes differ in their number of neutrons, not their number of protons, so both ¹H and ²H are not hydrogen. However, since their atomic structures are very similar except for the difference in mass, the spectra of the two isotopes would be expected to be very similar. The only difference would be a small shift in the wavelengths, with the heavier isotope having slightly longer wavelengths due to the greater mass of its nuclei.

Question 11

One atom of ¹³C has how many particles?

Accepted Answer

¹³C represents the chemical formula of a molecule, which consists of different atoms. Breaking down the formula shows: - S1: 1 sulfur atom - U1: 1 unknown element (not enough information to determine its atomic number) - P113: 113 phosphorus atoms - S1: 1 sulfur atom - S1: 1 sulfur atom - P0: 0 phosphorus atoms (does not contribute to the overall count) - C: 1 carbon atom To determine the number of particles (protons, neutrons, and electrons) in the atom, we need to know the atomic number of each element. - Sulfur (S) has an atomic number of 16, meaning it has 16 protons and 16 electrons. The sulfur atoms contribute a total of 2 x 16 = 32 particles. - Carbon (C) has an atomic number of 6, meaning it has 6 protons and 6 electrons. The carbon atom contributes 6 particles. - Phosphorus (P) has an atomic number of 15, meaning it has 15 protons and 15 electrons. The 113 phosphorus atoms contribute a total of 113 x 30 = 3,390 particles. We cannot determine the atomic number (and thus the number of particles) of the unknown element (U). Therefore, the total number of particles in the atom is: 32 + 6 + 3,390 = 3,428. The only answer choice that matches this count is B.

Question 12

The specific sequence of spectral line series emitted by excited hydrogen atoms, in order of increasing wavelength range, is:

Accepted Answer

The spectral line series emitted by excited hydrogen atoms in order of increasing wavelength range is Lyman, Balmer, Paschen. This is because the Lyman series corresponds to transitions from higher energy levels to the n=1 level, the Balmer series corresponds to transitions to the n=2 level, and the Paschen series corresponds to transitions to the n=3 level. Since the energy of the n=1 level is the highest, the wavelengths of the spectral lines in the Lyman series are the shortest, and as the energy levels decrease, the wavelengths of the spectral lines increase. Therefore, the correct order is Lyman, Balmer, Paschen.

Question 13

The upward Lyman series transitions in hydrogen begin with electrons in the ground state (n = 1), which is the state of most hydrogen atoms. Yet the Balmer series was studied first and was the basis of the early attempts to explain the lines. This is because:

Accepted Answer

The first few transitions in the Balmer series (n = 2 to n = infinity) are in the visible part of the spectrum, making them easier to observe and study. The upward transitions in the Lyman series (n = 1 to n = infinity) start with the ground state, but the resulting photons are in the ultraviolet part of the spectrum, making them more difficult to observe.

Question 14

Compare two electron transitions in hydrogen: n = 3 → n = 1 and n = 2 → n = 1. Which produces the photon with the higher frequency?

Accepted Answer

The transition from n = 3 to n = 1 involves a larger energy change than from n = 2 to n = 1, resulting in a photon with a higher frequency, according to the formula E = hf, where E is the energy difference, h is Planck's constant, and f is the frequency of the emitted photon.

Question 15

When a hydrogen atom is excited, it emits visible radiation. This radiation is predominantly in the:

Accepted Answer

When a hydrogen atom is excited and then returns to a lower energy level, it emits radiation in various spectral lines. The most prominent of these in the visible spectrum is the Balmer series, which includes the H-alpha line in the red part of the spectrum.

Question 16

The temperature of hydrogen gas is such that electrons are excited by atomic collisions up to the n = 3 atomic energy levels. Emission lines from which spectral sequences result when electrons return to the ground state?

Accepted Answer

When hydrogen gas is excited so that electrons are excited to the n=3 energy level, they can return to the ground state (n=1) by emitting photons of various wavelengths. The Balmer series corresponds to photons emitted by electrons returning from n=3 to n=2, while the Lyman series corresponds to photons emitted by electrons returning from higher energy levels, including n=3, to the ground state (n=1). Therefore, the spectral sequences resulting from the electrons returning to the ground state are the Balmer (visible) and Lyman (UV) series. The Paschen series corresponds to photons emitted by electrons returning from higher energy levels to n=3, but these photons are not emitted in this scenario as we are looking at electrons returning to the ground state. Therefore, option A is incorrect. Option B only includes the Lyman series, but the Balmer series is also present in this scenario. Therefore, option B is incorrect. Option D only includes the Balmer series, but the Lyman series is also present in this scenario. Therefore, option D is incorrect. This leaves us with option C, which correctly includes both the Balmer and Lyman series. Therefore, the answer is C.

Question 17

The strong ultraviolet spectral line emitted by hot hydrogen gas is known as the:

Accepted Answer

The Lyman alpha line is the strong ultraviolet spectral line emitted by hot hydrogen gas. The Balmer alpha and Paschen alpha lines are both visible or infrared lines emitted by hydrogen gas, but they are not ultraviolet. The 21-cm line is a radio emission line, not related to ultraviolet emission by hydrogen gas.

Question 18

The wavelengths λ of the emission lines from hot hydrogen gas depend on an integer n according to:

Accepted Answer

The wavelengths of the emission lines from hydrogen gas are determined by the Rydberg formula, which involves the term 1/n², where n is an integer representing the energy level.

Question 19

If the wavelengths of H_α and H_ß, the first two lines of the hydrogen Balmer series, are 656.3 nm and 486.2 nm, respectively, what is the wavelength of H_γ, the third line of the Balmer series?

Accepted Answer

The Balmer series formula is given by: $\frac{1}{\lambda}=R_H\left(\frac{1}{2^2}-\frac{1}{n^2}ight)$, where $R_H$ is the Rydberg constant for hydrogen and $n$ is the energy level of the electron. We are given the wavelengths of the first two lines, which correspond to $n=3$ and $n=4$:

$\frac{1}{\lambda_1}=R_H\left(\frac{1}{2^2}-\frac{1}{3^2}ight)$

$\frac{1}{\lambda_2}=R_H\left(\frac{1}{2^2}-\frac{1}{4^2}ight)$

We can solve these equations for $R_H$ by taking the reciprocal of both sides and subtracting them:

$\frac{1}{\lambda_2}-\frac{1}{\lambda_1}=R_H\left(\frac{1}{4^2}-\frac{1}{3^2}ight)$

$R_H=\frac{(\frac{1}{\lambda_2}-\frac{1}{\lambda_1})}{(\frac{1}{4^2}-\frac{1}{3^2})}=\frac{1}{364.6	ext{ nm}}$

Now we can use this value of $R_H$ to find the wavelength of the third line of the Balmer series, which corresponds to $n=5$:

$\frac{1}{\lambda_3}=R_H\left(\frac{1}{2^2}-\frac{1}{5^2}ight)$

$\lambda_3=\frac{1}{R_H\left(\frac{1}{2^2}-\frac{1}{5^2}ight)}=434.1	ext{ nm}$

Question 20

What type of radiation is emitted by hot hydrogen gas when electrons jump from the n = 8 level to the n = 7 level of the atoms?

Accepted Answer

When electrons jump from the n = 8 level to the n = 7 level of hydrogen atoms, they emit radiation in the infrared region of the electromagnetic spectrum. The wavelength of this radiation is given by the equation λ = 1.097 × 10^-2 nm (1/n1^2 - 1/n2^2), where n1 = 8 and n2 = 7. Plugging in these values gives a wavelength of approximately 19.05 μm, which is in the infrared range. Therefore, choice C is the correct answer.

Quiz 5: The Nature of Light

During a dust storm the Sun often appears to redden. This means that the particles of dust:

You are looking at a glowing field of hot lava from a satellite high above Earth's atmosphere. Hot lava emits most of its radiation in the infrared, and Earth's atmosphere is not completely transparent to infrared. What kind of spectrum will you see?

The overall diameter of a typical atom is about:

The typical size of an atom is:

The mass of a proton is:

The majority of the naturally occurring elements in the periodic table that decay radioactively are:

According to the arrangement of elements in the periodic table, which of the following elements would be expected to have chemical properties most similar to those of nitrogen, N, whose atomic number is 7?

Isotopes of a particular element in the periodic table have which nuclear property in common?

How many neutrons are there in the nucleus of the isotope ¹⁸O of oxygen?

How do the spectra of the two isotopes ¹H and ²H compare?

One atom of ¹³C has how many particles?

The specific sequence of spectral line series emitted by excited hydrogen atoms, in order of increasing wavelength range, is:

The upward Lyman series transitions in hydrogen begin with electrons in the ground state (n = 1) , which is the state of most hydrogen atoms. Yet the Balmer series was studied first and was the basis of the early attempts to explain the lines. This is because:

Compare two electron transitions in hydrogen: n = 3 → n = 1 and n = 2 → n = 1. Which produces the photon with the higher frequency?

When a hydrogen atom is excited, it emits visible radiation. This radiation is predominantly in the:

The temperature of hydrogen gas is such that electrons are excited by atomic collisions up to the n = 3 atomic energy levels. Emission lines from which spectral sequences result when electrons return to the ground state?

The strong ultraviolet spectral line emitted by hot hydrogen gas is known as the:

The wavelengths λ of the emission lines from hot hydrogen gas depend on an integer n according to:

If the wavelengths of H_α and H_ß, the first two lines of the hydrogen Balmer series, are 656.3 nm and 486.2 nm, respectively, what is the wavelength of H_γ, the third line of the Balmer series?

What type of radiation is emitted by hot hydrogen gas when electrons jump from the n = 8 level to the n = 7 level of the atoms?

Quiz 5: The Nature of Light

During a dust storm the Sun often appears to redden. This means that the particles of dust:

You are looking at a glowing field of hot lava from a satellite high above Earth's atmosphere. Hot lava emits most of its radiation in the infrared, and Earth's atmosphere is not completely transparent to infrared. What kind of spectrum will you see?

The overall diameter of a typical atom is about:

The typical size of an atom is:

The mass of a proton is:

The majority of the naturally occurring elements in the periodic table that decay radioactively are:

According to the arrangement of elements in the periodic table, which of the following elements would be expected to have chemical properties most similar to those of nitrogen, N, whose atomic number is 7? ​ ​

Isotopes of a particular element in the periodic table have which nuclear property in common?

How many neutrons are there in the nucleus of the isotope 18O of oxygen?

How do the spectra of the two isotopes 1H and 2H compare?

One atom of 13C has how many particles?

The specific sequence of spectral line series emitted by excited hydrogen atoms, in order of increasing wavelength range, is:

The upward Lyman series transitions in hydrogen begin with electrons in the ground state (n = 1) , which is the state of most hydrogen atoms. Yet the Balmer series was studied first and was the basis of the early attempts to explain the lines. This is because:

Compare two electron transitions in hydrogen: n = 3 → n = 1 and n = 2 → n = 1. Which produces the photon with the higher frequency?

When a hydrogen atom is excited, it emits visible radiation. This radiation is predominantly in the:

The temperature of hydrogen gas is such that electrons are excited by atomic collisions up to the n = 3 atomic energy levels. Emission lines from which spectral sequences result when electrons return to the ground state?

The strong ultraviolet spectral line emitted by hot hydrogen gas is known as the:

The wavelengths λ of the emission lines from hot hydrogen gas depend on an integer n according to:

If the wavelengths of Hα and Hß, the first two lines of the hydrogen Balmer series, are 656.3 nm and 486.2 nm, respectively, what is the wavelength of Hγ, the third line of the Balmer series?

What type of radiation is emitted by hot hydrogen gas when electrons jump from the n = 8 level to the n = 7 level of the atoms?

According to the arrangement of elements in the periodic table, which of the following elements would be expected to have chemical properties most similar to those of nitrogen, N, whose atomic number is 7?

How many neutrons are there in the nucleus of the isotope ¹⁸O of oxygen?

How do the spectra of the two isotopes ¹H and ²H compare?

One atom of ¹³C has how many particles?

If the wavelengths of H_α and H_ß, the first two lines of the hydrogen Balmer series, are 656.3 nm and 486.2 nm, respectively, what is the wavelength of H_γ, the third line of the Balmer series?