Chapter 5, Problem 52E

Determine whether each statement that follows is true or false.

a) Dalton proposed that atoms of different elements always combine on a one-to-one basis.

b) According to Dalton, all oxygen atoms have the same diameter.

c) The mass of an electron is about the same as the mass of a proton.

d) There are subatomic particles in addition to the electron, proton, and neutron.

e) The mass of an atom is uniformly distributed throughout the atom.

f) Most of the particles fired into the gold foil in the Rutherford experiment were not deflected.

g) The masses of the proton and electron are equal but opposite in sign.

h) Isotopes of an element have different electrical charges.

i) The atomic number of an element is the number of particles in the nucleus of an atom of that element.

j) An oxygen $-16$ atom has the same number of protons as an $\text{oxygen}$ $-17$ atom.

k) The nuclei of nitrogen atoms have a different number of protons from the nuclei of any other element.

l) Neutral atoms of sulfur have a different number of electrons from neutral atoms of any other element.

m) Isotopes of different elements that exhibit the same mass number exhibit similar chemical behavior.

n) The mass number of carbon $-\text{12}$ atom is exactly $\text{12}\text{g}$.

o) Periods are arranged vertically in the periodic table.

p) The atomic mass of the second element in the farthest right column of the periodic table is $10\text{u}$.

q) $\text{Nb}$ is the symbol of the element for which $\text{Z}=41$.

r) Elements in the same column of the periodic table have similar properties.

s) The element for which $\text{Z}=38$ is in both Group $\text{2A}/2$ and the fifth period.

Interpretation Introduction

(a)

Interpretation:

Whether the statement, “Dalton proposed that atoms of different elements always combine on a one-to-one basis” is true or false is to be stated.

Concept introduction:

Dalton realized that the Law of Conservation of Mass, the Law of Definite Composition and the Law of Multiple Proportions could be explained if matter was considered to be made up of indivisible particles called atoms. Later, the indivisibility of atoms was proved to be untrue. Atoms comprise of smaller particles which are termed as subatomic particles.

Answer to Problem 52E

The statement, “Dalton proposed that atoms of different elements always combine on a one-to-one basis” is false.

Explanation of Solution

The law of multiple proportions was deduced from Dalton’s atomic theory. According to this law, when two elements combine together to form more than one compound then different weights of one element that combine with a fixed weight of the other element are in the ratio of simple whole numbers. Carbon and oxygen atoms combine in a $1:1$ ratio to form carbon monoxide while carbon dioxide is formed when carbon and oxygen combine in a $1:2$ ratio. Therefore, the statement, “Dalton proposed that atoms of different elements always combine on a one-to-one basis” is false.

Conclusion

The statement, “Dalton proposed that atoms of different elements always combine on a one-to-one basis” is false.

Interpretation Introduction

(b)

Interpretation:

Whether the statement, “According to Dalton, all oxygen atoms have the same diameter” is true or false is to be stated.

Concept introduction:

Dalton realized that the Law of Conservation of Mass, the Law of Definite Composition and the Law of Multiple Proportions could be explained if matter was considered to be made up of indivisible particles called atoms. Later, the indivisibility of atoms was proved to be untrue. Atoms comprise of smaller particles which are termed as subatomic particles.

Answer to Problem 52E

The statement, “According to Dalton, all oxygen atoms have the same diameter” is true.

Explanation of Solution

Dalton’s atomic theory states that a particular element is composed of one type of atoms. All the atoms present in a particular element are identical. Therefore, the statement, “According to Dalton, all oxygen atoms have the same diameter” is true.

Conclusion

The statement, “According to Dalton, all oxygen atoms have the same diameter” is true.

Interpretation Introduction

(c)

Interpretation:

Whether the statement, “The mass of an electron is about the same as the mass of a proton” is true or false is to be stated.

Concept introduction:

An atom is made up of three subatomic particles-neutrons, protons, and electrons. Neutron and protons are present in the nucleus of the atom, whereas electrons are revolving outside the nucleus in an atom. In a neutral atom number of electrons and the number of protons are equal.

Answer to Problem 52E

The statement, “The mass of an electron is about the same as the mass of a proton” is false.

Explanation of Solution

Electrons, neutrons and protons are the three subatomic particles present in an atom. The mass of an electron is $9.11\times {10}^{-31}\text{kg}$. The mass of a proton is $1.67\times 10{}^{-27}\text{kg}$. Therefore, a proton is heavier than an electron. Therefore, the statement, “The mass of an electron is about the same as the mass of a proton” is false.

Conclusion

The statement, “The mass of an electron is about the same as the mass of a proton” is false.

Interpretation Introduction

(d)

Interpretation:

Whether the statement, “There are subatomic particles in addition to the electron, proton, and neutron” is true or false is to be stated.

Concept introduction:

An atom is made up of three subatomic particles-neutrons, protons, and electrons. Neutron and protons are present in the nucleus of the atom, whereas electrons are revolving outside the nucleus in an atom. In a neutral atom number of electrons and the number of protons are equal.

Answer to Problem 52E

The statement, “There are subatomic particles in addition to the electron, proton, and neutron” is true.

Explanation of Solution

Dalton’s theory of matter being composed of indivisible atoms was proved to be untrue. It was found that atoms could be divided into subatomic particles called electrons, neutrons and protons. It was later found that proton and neutron were made up of even smaller subatomic particles called positron, muon and neutrino. Therefore, the statement, “There are subatomic particles in addition to the electron, proton, and neutron” is true.

Conclusion

The statement, “There are subatomic particles in addition to the electron, proton, and neutron” is true.

Interpretation Introduction

(e)

Interpretation:

Whether the statement, “The mass of an atom is uniformly distributed throughout the atom” is true or false is to be stated.

Concept introduction:

An atom is made up of three subatomic particles-neutrons, protons, and electrons. Neutron and protons are present in the nucleus of the atom, whereas electrons are revolving outside the nucleus in an atom. In a neutral atom number of electrons and the number of protons are equal.

Answer to Problem 52E

The statement, “The mass of an atom is uniformly distributed throughout the atom” is false.

Explanation of Solution

Rutherford conducted experiments to determine the structure of the atom. It was concluded from the experiments that the mass of the atom is almost entirely concentrated in the nucleus which contains protons and neutrons. Therefore, the statement, “The mass of an atom is uniformly distributed throughout the atom” is false.

Conclusion

The statement, “The mass of an atom is uniformly distributed throughout the atom” is false.

Interpretation Introduction

(f)

Interpretation:

Whether the statement, “Most of the particles fired into the gold foil in the Rutherford experiment were not deflected” is true or false is to be stated.

Concept introduction:

The nuclear model of the atom is a result of Rutherford’s scattering experiments to determine the structure of an atom. According to the nuclear model of an atom, atoms consist of a positively charged dense nucleus surrounded by negatively charged electrons which move in an orbit around the nucleus.

Answer to Problem 52E

The statement, “Most of the particles fired into the gold foil in the Rutherford experiment were not deflected” is true.

Explanation of Solution

In Rutherford’s experiment, a narrow beam of positively charged alpha particles were directed at a thin gold foil. As the alpha particle struck the fluorescent screen, the screen illuminated. Most of the alpha particles passed straight through the foil. Therefore, the statement, “Most of the particles fired into the gold foil in the Rutherford experiment were not deflected” is true.

Conclusion

The statement, “Most of the particles fired into the gold foil in the Rutherford experiment were not deflected” is true.

Interpretation Introduction

(g)

Interpretation:

Whether the statement, “The masses of the proton and electron are equal but opposite in sign” is true or false is to be stated.

Concept introduction:

An atom is made up of three subatomic particles-neutrons, protons, and electrons. Neutron and protons are present in the nucleus of the atom, whereas electrons are revolving outside the nucleus in an atom. In a neutral atom number of electrons and the number of protons are equal.

Answer to Problem 52E

The statement, “The masses of the proton and electron are equal but opposite in sign” is false.

Explanation of Solution

Electrons, neutrons and protons are the three subatomic particles present in an atom. Electrons are negatively charged particles. The mass of an electron is $9.11\times {10}^{-31}\text{kg}$. Protons are positively charged particles. The mass of a proton is $1.67\times 10{}^{-27}\text{kg}$. This means that a proton is heavier than an electron. Therefore, the statement, “The masses of the proton and electron are equal but opposite in sign” is false.

Conclusion

The statement, “The masses of the proton and electron are equal but opposite in sign” is false.

Interpretation Introduction

(h)

Interpretation:

Whether the statement, “Isotopes of an element have different electrical charges” is true or false is to be stated.

Concept introduction:

If two atoms of an element have different number of neutrons in them, then they are considered as isotopes of each other. Therefore, the mass number of each isotope is different from each other. The mass number of an isotope is known as its isotopic mass.

Answer to Problem 52E

The statement, “Isotopes of an element have different electrical charges” is false.

Explanation of Solution

Isotopes are different species of the same element which have the same atomic number but different mass number. Hydrogen has three isotopes, ${}_{\text{1}}^{\text{1}}\text{H,}{}_{\text{1}}^{\text{2}}\text{H,}{}_{\text{1}}^{\text{3}}\text{H}$. The subscripts indicate atomic number and superscripts indicate the mass number. The mass number is different due to different number of neutrons present in each isotope. Neutrons do not carry electrical charge. As a result, isotopes of an element have the same electrical charges. Therefore, the statement, “Isotopes of an element have different electrical charges” is false.

Conclusion

The statement, “Isotopes of an element have different electrical charges” is false.

Interpretation Introduction

(i)

Interpretation:

Whether the statement, “The atomic number of an element is the number of particles in the nucleus of an atom of that element” is true or false is to be stated.

Concept introduction:

An atom is made up of three subatomic particles-neutrons, protons, and electrons. Neutron and protons are present in the nucleus of the atom, whereas electrons are revolving outside the nucleus in an atom. In a neutral atom number of electrons and the number of protons are equal.

Answer to Problem 52E

The statement, “The atomic number of an element is the number of particles in the nucleus of an atom of that element” is false.

Explanation of Solution

The nucleus of an atom contains protons and neutrons. The number of protons in the nucleus of an atom is equal to the atomic number of that element. For a neutral element, the number of electrons is equal to the number of protons. Therefore, the statement, “The atomic number of an element is the number of particles in the nucleus of an atom of that element” is false.

Conclusion

The statement, “The atomic number of an element is the number of particles in the nucleus of an atom of that element” is false.

Interpretation Introduction

(j)

Interpretation:

Whether the statement, “An $\text{oxygen}-16$ atom has the same number of protons as an $\text{oxygen}-17$ atom” is true or false is to be stated.

Concept introduction:

If two atoms of an element have different number of neutrons in them, then they are considered as isotopes of each other. Therefore, the mass number of each isotope is different from each other. The mass number of an isotope is known as its isotopic mass.

Answer to Problem 52E

The statement, “An oxygen $-16$ atom has the same number of protons as an $\text{oxygen}$$-17$ atom” is true.

Explanation of Solution

The nucleus of an atom contains protons and neutrons. The number of protons in the nucleus of an atom is equal to the atomic number of that element. Isotopes are different species of the same element which have the same atomic number but different mass number. Oxygen $-16$ and oxygen $-17$ are isotopes. Therefore, they have the same atomic number. As atomic number is equal to the number of protons, they have the same number of protons. Therefore, the statement, “An oxygen $-16$ atom has the same number of protons as an $\text{oxygen}$$-17$ atom” is true.

Conclusion

The statement, “An oxygen $-16$ atom has the same number of protons as an $\text{oxygen}$$-17$ atom” is true.

Interpretation Introduction

(k)

Interpretation:

Whether the statement, “The nuclei of nitrogen atoms have a different number of protons from the nuclei of any other element” is true or false is to be stated.

Concept introduction:

An atom is made up of three subatomic particles-neutrons, protons, and electrons. Neutron and protons are present in the nucleus of the atom, whereas electrons are revolving outside the nucleus in an atom. In a neutral atom number of electrons and the number of protons are equal.

Answer to Problem 52E

The statement, “The nuclei of nitrogen atoms have a different number of protons from the nuclei of any other element” is true.

Explanation of Solution

The number of protons present in the nucleus of an atom is equal to the atomic number of that element. Different elements have different atomic numbers. If the atomic number changes, the number of protons present in the nucleus also changes. Therefore, the statement, “The nuclei of nitrogen atoms have a different number of protons from the nuclei of any other element” is true.

Conclusion

The statement, “The nuclei of nitrogen atoms have a different number of protons from the nuclei of any other element” is true.

Interpretation Introduction

(l)

Interpretation:

Whether the statement, “Neutral atoms of sulfur have a different number of electrons from neutral atoms of any other element” is true or false is to be stated.

Concept introduction:

An atom is made up of three subatomic particles-neutrons, protons, and electrons. Neutron and protons are present in the nucleus of the atom, whereas electrons are revolving outside the nucleus in an atom. In a neutral atom number of electrons and the number of protons are equal.

Answer to Problem 52E

The statement, “Neutral atoms of sulfur have a different number of electrons from neutral atoms of any other element” is true.

Explanation of Solution

The atomic number of an element is equal to the number of protons. For a neutral atom, the number of protons is equal to the number of electrons. Different elements have different atomic numbers. If the atomic number changes, the number of protons and electrons present in the nucleus also changes. Therefore, the statement, “Neutral atoms of sulfur have a different number of electrons from neutral atoms of any other element” is true.

Conclusion

The statement, “Neutral atoms of sulfur have a different number of electrons from neutral atoms of any other element” is true.

Interpretation Introduction

(m)

Interpretation:

Whether the statement, “Isotopes of different elements that exhibit the same mass number exhibit similar chemical behavior” is true or false is to be stated.

Concept introduction:

If two atoms of an element have different number of neutrons in them, then they are considered as isotopes of each other. Therefore, the mass number of each isotope is different from each other. The mass number of an isotope is known as its isotopic mass.

Answer to Problem 52E

The statement, “Isotopes of different elements that exhibit the same mass number exhibit similar chemical behavior” is false.

Explanation of Solution

Isotopes are different species of the same element which have the same atomic number but different mass number. Hydrogen has three isotopes, ${}_{\text{1}}^{\text{1}}\text{H,}{}_{\text{1}}^{\text{2}}\text{H,}{}_{\text{1}}^{\text{3}}\text{H}$. The subscript indicates atomic number and superscript indicates the mass number. The mass number is different due to different number of neutrons present in each isotope. Isotopes of different elements which have the same mass number exhibit different behavior as the elements are different. Therefore, the statement, “Isotopes of different elements that exhibit the same mass number exhibit similar chemical behavior” is false.

Conclusion

The statement, “Isotopes of different elements that exhibit the same mass number exhibit similar chemical behavior” is false.

Interpretation Introduction

(n)

Interpretation:

Whether the statement, “The mass number of carbon $-\text{12}$ atom is exactly $\text{12}\text{g}$” is true or false is to be stated.

Concept introduction:

If two atoms of an element have a different number of neutrons in them, then they are considered as isotopes of each other. Therefore, the mass number of each isotope is different from each other. The mass number of an isotope is known as its isotopic mass.

Answer to Problem 52E

The statement, “The mass number of carbon $-\text{12}$ atom is exactly $\text{12}\text{g}$” is false.

Explanation of Solution

The relation between $\text{gram}$ and $\text{u}$ is given below.

$\text{1}\text{u}=1.66\times {10}^{-24}\text{g}$

The conversion of $\text{12}\text{g}$ into $\text{gram}$ is done as shown below.

$\begin{array}{rll}\text{12}\text{u}& =& 12\text{u}\times \frac{1.66\times {10}^{-24}\text{g}}{1\text{u}}\\ & =& 19.92\times {10}^{-24}\text{g}\end{array}$

Therefore, statement, “The mass number of carbon $-\text{12}$ atom is exactly $\text{12}\text{g}$” is false.

Conclusion

The statement, “The mass number of carbon $-\text{12}$ atom is exactly $\text{12}\text{g}$” is false.

Interpretation Introduction

(o)

Interpretation:

Whether the statement, “Periods are arranged vertically in the periodic table” is true or false is to be stated.

Concept introduction:

The elements in a modern periodic table are arranged in an increasing order of their atomic number. There are $7$ periods and $18$ groups in a modern periodic table. They are categorized into groups based on the type of energy sublevel that the last valence electron of the element enters.

Answer to Problem 52E

The statement, “Periods are arranged vertically in the periodic table” is false.

Explanation of Solution

Periodic table consists of vertical columns and horizontal rows. Horizontal rows are known as periods and vertical columns are known as groups. Periods are arranged horizontally in the periodic table. Therefore, the statement, “Periods are arranged vertically in the periodic table” is false.

Conclusion

The statement, “Periods are arranged vertically in the periodic table” is false.

Interpretation Introduction

(p)

Interpretation:

Whether the statement, “The atomic mass of the second element in the farthest right column is $10\text{u}$” is true or false is to be stated.

Concept introduction:

The elements in a modern periodic table are arranged in an increasing order of their atomic number. There are $7$ periods and $18$ groups in a modern periodic table. They are categorized into groups based on the type of energy sublevel that the last valence electron of the element enters.

Answer to Problem 52E

The statement, “The atomic mass of the second element in the farthest right column is $10\text{u}$” is false.

Explanation of Solution

Periodic table consists of vertical columns and horizontal rows. Horizontal rows are known as periods and vertical columns are known as groups. The second element in the farthest right column is neon. The atomic number of neon is $10$. The mass number of neon is not $10\text{u}$. Therefore, the statement, “The atomic mass of the second element in the farthest right column is $10\text{u}$” is false.

Conclusion

The statement, “The atomic mass of the second element in the farthest right column is $10\text{u}$” is false.

Interpretation Introduction

(q)

Interpretation:

Whether the statement, “$\text{Nb}$ is the symbol of the element for which $\text{Z}=41$” is true or false is to be stated.

Concept introduction:

The elements in a modern periodic table are arranged in an increasing order of their atomic number. There are $7$ periods and $18$ groups in a modern periodic table. They are categorized into groups based on the type of energy sublevel that the last valence electron of the element enters.

Answer to Problem 52E

The statement, “$\text{Nb}$ is the symbol of the element for which $\text{Z}=41$” is true.

Explanation of Solution

Periodic table consists of vertical columns and horizontal rows. Horizontal rows are known as periods and vertical columns are known as groups. From the periodic table, the element with atomic number $41$ is niobium. The symbol of niobium is $\text{Nb}$. Therefore, the statement, “$\text{Nb}$ is the symbol of the element for which $\text{Z}=41$” is true.

Conclusion

The statement, “$\text{Nb}$ is the symbol of the element for which $\text{Z}=41$” is true.

Interpretation Introduction

(r)

Interpretation:

Whether the statement, “Elements in the same column of the periodic table have similar properties” is true or false is to be stated.

Concept introduction:

The elements in a modern periodic table are arranged in an increasing order of their atomic number. There are $7$ periods and $18$ groups in a modern periodic table. They are categorized into groups based on the type of energy sublevel that the last valence electron of the element enters.

Answer to Problem 52E

The statement, “Elements in the same column of the periodic table have similar properties” is true.

Explanation of Solution

In the modern periodic table, the horizontal rows are known as periods. The periods are numbered from top to bottom. The first period contains $2$ elements, the second and third contain $8$ elements and the fourth and fifth contain $18$ elements. The sixth and seventh period contain $32$ elements. The vertical columns in a periodic table are known as groups. Elements with similar properties are placed within one group. Groups are also termed as family. Therefore, the statement, “Elements in the same column of the periodic table have similar properties” is true.

Conclusion

The statement, “Elements in the same column of the periodic table have similar properties” is true.

Interpretation Introduction

(s)

Interpretation:

Whether the statement, “The element for which $\text{Z}=38$ is in both Group $\text{2A}/2$ and the fifth period” is true or false is to be stated.

Concept introduction:

The elements in a modern periodic table are arranged in an increasing order of their atomic number. There are $7$ periods and $18$ groups in a modern periodic table. They are categorized into groups based on the type of energy sublevel that the last valence electron of the element enters.

Answer to Problem 52E

The statement, “The element for which $\text{Z}=38$ is in both Group $\text{2A}/2$ and the fifth period” is true.

Explanation of Solution

In the modern periodic table, the horizontal rows are known as periods. The periods are numbered from top to bottom. The vertical columns in a periodic table are known as groups. Elements with similar properties are placed within one group. From the periodic table, the element with the atomic number $38$ is strontium. Strontium is present in Group $\text{2A}/2$ and the fifth period. Therefore, the statement, “The element for which $\text{Z}=38$ is in both Group $\text{2A}/2$ and the fifth period” is true.

Conclusion

The statement, “The element for which $\text{Z}=38$ is in both Group $\text{2A}/2$ and the fifth period” is true.