Question 1

The star P Cygni (in the constellation Cygnus,the Swan)is surrounded by an extensive low-density atmosphere.It has a bright,continuous spectrum with many narrow,dark absorption lines and a few bright emission lines.The bright emission lines are produced by:
A) the low-density atmosphere of the star emitting light in all directions.
B) only the part of the low-density atmosphere that is between Earth and the surface of the star.
C) all parts of the star, the stellar surface, and the atmosphere, equally.
D) the hot, dense, opaque gas at or near the star's surface.

Accepted Answer

The bright emission lines in the spectrum of P Cygni are produced by the low-density atmosphere of the star emitting light in all directions. This phenomenon occurs when the gas in the atmosphere is excited and emits light at specific wavelengths, creating emission lines in the spectrum.

Question 2

The force that holds the atomic nucleus together is:
A) gravitational.
B) electrical.
C) weak nuclear.
D) strong nuclear.

Accepted Answer

The force that holds the atomic nucleus together is the strong nuclear force. This force is stronger than the electrical force (which repels the positively charged protons in the nucleus) and keeps the protons and neutrons tightly bound together. The gravitational force is too weak to hold the particles together in the nucleus, and the weak nuclear force only acts over very short distances and is responsible for certain radioactive decays.

Question 3

Two different isotopes of the element selenium will have the same number of:
A) protons but a different number of neutrons.
B) protons but a different number of electrons.
C) protons and neutrons, but they are arranged differently in the nucleus.
D) neutrons but a different number of protons.

Accepted Answer

Isotopes have the same number of protons (which determine the element) but a different number of neutrons, which results in different mass numbers.

Question 4

One isotope of iron has an atomic number of 26.How many protons are there in its nucleus?
A) The atomic number is not related to the number of protons in the nucleus, which could be any number between 1 and 26.
B) 1 less than 26, or 25
C) 26
D) 56

Accepted Answer

The atomic number of an element represents the number of protons in its nucleus. Therefore, since the isotope of iron has an atomic number of 26, it must have 26 protons in its nucleus.

Question 5

A hydrogen atom in a low-density,hot gas gives off what type of spectrum?
A) a series of emission lines at uniform wavelength spacings
B) a uniform spectrum crossed by numerous dark absorption lines
C) a series of emission lines spaced in a mathematical sequence
D) a uniform spectrum containing all colors

Accepted Answer

A hydrogen atom in a low-density, hot gas gives off a series of emission lines spaced in a mathematical sequence, known as the hydrogen spectral series. This is due to the electron transitions between different energy levels in the atom, which emit photons with specific energies and wavelengths. The spacing of the lines follows a mathematical pattern, with each series corresponding to a different set of transitions.

Question 6

The basic makeup of an atom is:
A) small, negatively charged particles orbiting around a central positive charge.
B) negative and positive charges mixed uniformly through the volume of the atom.
C) miniature planets, possibly with miniature people, gravitationally bound in orbits around a miniature star.
D) small, positively charged particles orbiting around a central negative charge.

Accepted Answer

The basic structure of an atom consists of electrons, which are negatively charged particles, orbiting around a nucleus that contains protons, which have a positive charge. This configuration aligns with choice A, where the electrons are the small negatively charged particles and the nucleus is the central positive charge.

Question 7

The star P Cygni (in the constellation Cygnus,the Swan)is surrounded by an extensive low-density atmosphere.It has a bright,continuous spectrum with many narrow,dark absorption lines and a few bright emission lines.The dark absorption lines are produced by:
A) only the part of the low-density atmosphere that is between Earth and the surface of the star.
B) the hot, low-density atmosphere of the star emitting light in all directions.
C) all parts of the star, the stellar surface, and the atmosphere, equally.
D) the hot, dense, opaque gas of the star's surface.

Accepted Answer

The dark absorption lines are produced by the part of the low-density atmosphere that is between Earth and the surface of the star, as it absorbs specific wavelengths of light from the continuous spectrum emitted by the star's surface.

Question 8

How many neutrons are there in the nucleus of the isotope ¹⁷O of oxygen?
A) 9
B) 7
C) 8
D) 17

Accepted Answer

The isotope ¹⁷O has a mass number of 17. Oxygen has an atomic number of 8, which means it has 8 protons. The number of neutrons is the mass number minus the number of protons: 17 - 8 = 9 neutrons.

Question 9

An atom consists of:
A) negatively charged electrons moving around a very small but massive, positively charged nucleus.
B) neutrons orbiting an electrically neutral nucleus composed of protons and electrons.
C) positive protons, neutral neutrons, and negative electrons orbiting a small but massive black hole.
D) negatively charged electrons and positively charged protons mixed uniformly throughout the volume of the atom.

Accepted Answer

An atom consists of negatively charged electrons moving around a very small but massive, positively charged nucleus. The nucleus is composed of positively charged protons and neutral neutrons.

Question 10

A sample of hydrogen gas is heated and produces a spectrum of bright lines.A blackbody spectrum is observed through a cooler sample of hydrogen gas.This situation also produces a line spectrum,and the locations of these lines:
A) are in exactly the same places occupied by the lines in the first bright line spectrum. In fact, these two bright line spectra are identical in every way.
B) are in exactly the same places occupied by the lines in the bright line spectra. These lines, however, are dark absorption lines.
C) are in different places from the lines in the bright line spectrum.
D) match the lines in the bright line spectrum. However, there are many additional lines in this dark line spectrum.

Accepted Answer

When a blackbody spectrum is observed through a cooler sample of hydrogen gas, it produces a dark absorption line spectrum. The locations of these lines are in exactly the same places occupied by the lines in the bright line spectra. However, they are dark because they appear as absorption lines instead of emission lines. This is due to the cooler gas absorbing certain wavelengths of light, creating dark lines in the spectrum. Therefore, the best choice is B.

Question 11

The position of an element in the periodic table,its atomic number,is equal to the:
A) number of protons in the nucleus of the atom.
B) number of the column in which the element is placed in the periodic table.
C) sum of the number of neutrons and protons in the nucleus of the atom.
D) number of neutrons in the nucleus of the atom.

Accepted Answer

The atomic number of an element is defined as the number of protons present in the nucleus of an atom.

Question 12

The physical force that holds the components of an atom together is the:
A) nuclear force between protons and neutrons.
B) gravitational force between the massive nucleus and the much less massive electrons.
C) centrifugal force produced on electrons by their orbital motion around the nucleus.
D) electromagnetic attraction between the positive nucleus and the negative electrons.

Accepted Answer

The physical force that holds the components of an atom together is the electromagnetic attraction between the positive nucleus and the negative electrons. This force is responsible for keeping the electrons in their orbits around the nucleus, and for holding the nucleus together despite the repulsion between its positively charged protons.

Question 13

The property of a neutral atom that defines its chemical behavior and fixes its position in the periodic table is:
A) its physical size.
B) the number of neutrons in the nucleus.
C) the number of protons and neutrons in its nucleus.
D) the number of protons in the nucleus.

Accepted Answer

The number of protons in the nucleus, also known as the atomic number, defines the element and determines its chemical behavior. This number fixes the element's position in the periodic table as elements are arranged according to their increasing atomic number. The physical size of the atom and the number of neutrons in the nucleus are important properties but do not define the element or its position in the periodic table.

Question 14

The sodium D lines are a closely spaced pair of spectral lines in neutral sodium.They are present as absorption lines in the spectrum of the Sun's photosphere because of traces of sodium there.What would you expect to see if sunlight is passed through a cool sodium vapor in the laboratory and then observed with a spectroscope?
A) The sodium D lines will become brighter.
B) The sodium D lines will become darker.
C) The two absorption lines will merge into a single line.
D) No change in the sodium D lines will result.

Accepted Answer

When sunlight is passed through a cool sodium vapor in the laboratory, the sodium atoms in the vapor will absorb some of the light at the same wavelength as the sodium D lines. This will result in a decrease in the intensity of the sodium D lines, making them appear darker in the spectrum observed with a spectroscope. Therefore, option B is the correct choice.

Question 15

The parameter of an atom that defines its unique position in the periodic table is:
A) the number of protons in the nucleus.
B) the number of protons and neutrons in the nucleus.
C) its temperature.
D) its size.

Accepted Answer

The number of protons in the nucleus is known as the atomic number, which is the defining characteristic of an element and determines its unique position in the periodic table.

Question 16

The position of an element in the periodic table is directly related to the:
A) mass of the nucleus of the atom.
B) number of protons in the atomic nucleus and hence to its positive charge.
C) total number of protons and neutrons in the atomic nucleus.
D) number of electrons in the atomic nucleus and hence to its negative charge.

Accepted Answer

The position of an element in the periodic table is directly related to the number of protons in the atomic nucleus, which is also known as the atomic number. The atomic number determines the element's chemical properties and its position in the periodic table. Therefore, option B, which states that the position of an element in the periodic table is related to the number of protons in the atomic nucleus, is the best choice.

Question 17

The New Zealand physicist Lord Rutherford and his colleagues in England demonstrated the existence of the very small but massive nucleus inside every atom in which crucial experiment?
A) deflection and occasional reflection backward of energetic nuclear particles from a beam aimed at a thin metal sheet
B) measurement of the spectrum of light emitted from a thin, heated metal sheet
C) detection of the motion of electrons around the nucleus by the use of a very powerful microscope
D) emission of electrons from a metal surface illuminated with UV light

Accepted Answer

Lord Rutherford and his colleagues demonstrated the existence of the nucleus through an experiment in which they aimed a beam of energetic nuclear particles at a thin metal sheet and observed the deflection and occasional reflection backward of these particles, indicating the presence of a small but massively dense center in the atom.

Question 18

The four fundamental forces in nature include all of the following forces EXCEPT ONE.Which one is the exception?
A) nuclear
B) gravitational
C) friction
D) electromagnetic

Accepted Answer

The four fundamental forces in nature are nuclear, gravitational, electromagnetic, and weak forces. Friction is not one of the fundamental forces; rather, it is a type of force that arises from the interaction between two surfaces in contact.

Question 19

Isotopes of a particular element in the periodic table have the same number of _____ in the nucleus.
A) neutrons but different numbers of protons and electrons
B) protons but different numbers of neutrons
C) neutrons but different numbers of protons
D) protons and neutrons

Accepted Answer

Isotopes of an element have the same number of protons (which determines the element) but different numbers of neutrons, which results in different atomic masses.

Question 20

An atom is now known to consist of a:
A) positively charged crystal structure with electrons moving within it.
B) small, positively charged black hole with electrons held in orbits around it by intense gravitational forces.
C) uniform distribution of positively charged matter with electrons embedded in it.
D) small, massive, electrically charged core surrounded by electrons.

Accepted Answer

According to modern atomic theory, an atom consists of a small, massive, electrically charged core called a nucleus, which contains positively charged protons and neutral particles called neutrons, surrounded by electrons that occupy various energy levels in shells surrounding the nucleus. The nucleus is held together by the strong nuclear force, while the electrons are attracted to the positively charged nucleus by the electromagnetic force.

Quiz 3: Light and Telescopes

The star P Cygni (in the constellation Cygnus,the Swan) is surrounded by an extensive low-density atmosphere.It has a bright,continuous spectrum with many narrow,dark absorption lines and a few bright emission lines.The bright emission lines are produced by:

The force that holds the atomic nucleus together is:

Two different isotopes of the element selenium will have the same number of:

One isotope of iron has an atomic number of 26.How many protons are there in its nucleus?

A hydrogen atom in a low-density,hot gas gives off what type of spectrum?

The basic makeup of an atom is:

The star P Cygni (in the constellation Cygnus,the Swan) is surrounded by an extensive low-density atmosphere.It has a bright,continuous spectrum with many narrow,dark absorption lines and a few bright emission lines.The dark absorption lines are produced by:

How many neutrons are there in the nucleus of the isotope ¹⁷O of oxygen?

An atom consists of:

A sample of hydrogen gas is heated and produces a spectrum of bright lines.A blackbody spectrum is observed through a cooler sample of hydrogen gas.This situation also produces a line spectrum,and the locations of these lines:

The position of an element in the periodic table,its atomic number,is equal to the:

The physical force that holds the components of an atom together is the:

The property of a neutral atom that defines its chemical behavior and fixes its position in the periodic table is:

The parameter of an atom that defines its unique position in the periodic table is:

The position of an element in the periodic table is directly related to the:

The New Zealand physicist Lord Rutherford and his colleagues in England demonstrated the existence of the very small but massive nucleus inside every atom in which crucial experiment?

The four fundamental forces in nature include all of the following forces EXCEPT ONE.Which one is the exception?

Isotopes of a particular element in the periodic table have the same number of _____ in the nucleus.

An atom is now known to consist of a: