Chemistry Chapter 5 - The Periodic Law

Questions and Answers

In the modern periodic table, elements are ordered according to which of these?

According to Mendeleev's original design.

According to decreasing atomic mass.

Based on when they were discovered.

According to increasing atomic number. (correct)

Mendeleev noticed that certain similarities in the chemical properties of elements appeared at regular intervals when the elements were arranged in order of increasing?

Atomic number

Atomic mass (correct)

Density

Reactivity

What does the modern periodic law state?

The chemical properties of elements can be grouped according to periodicity, but physical properties cannot.

Electrons exhibit properties of both particles and waves.

No two electrons with the same spin can be found in the same place in an atom.

The physical and chemical properties of an element are functions of its atomic number. (correct)

The discovery of the noble gases changed Mendeleev's periodic table by adding a new?

Group Signup and view all the answers

The most distinctive property of the noble gases is that they are?

Largely unreactive Signup and view all the answers

Lithium, the first element in Group 1, has an atomic number of 3. The second element in this group has an atomic number of?

11 Signup and view all the answers

An isotope of fluorine has a mass number of 19 and an atomic number of 9. How many protons are in this atom?

9 Signup and view all the answers

An isotope of fluorine has a mass number of 19 and an atomic number of 9. How many neutrons are in this atom?

10 Signup and view all the answers

A certain isotope contains 53 protons, 78 neutrons, and 54 electrons. What is its atomic number?

53 Signup and view all the answers

A certain isotope contains 53 protons, 78 neutrons, and 54 electrons. What is the mass number of this atom?

131 Signup and view all the answers

A certain isotope contains 53 protons, 78 neutrons, and 54 electrons. What is the name of this element?

Iodine Signup and view all the answers

In a modern periodic table, every element is a member of both a horizontal row and a vertical column. Which one is the group, and which one is the period?

The group is the vertical column, and the period is the horizontal row. Signup and view all the answers

Explain the distinction between atomic mass and atomic number of an element.

The atomic number is the number of protons in an atom. The atomic mass is a weighted average of the masses of the naturally occurring isotopes of that element. Signup and view all the answers

There are 18 columns in the periodic table; each has a group number. Give the group numbers that make up each of the following blocks: s block, p block, d block.

1-2, 13-18, 3-12 Signup and view all the answers

When an electron is added to a neutral atom, energy is?

Either absorbed or released Signup and view all the answers

The energy required to remove an electron from a neutral atom is the atom's?

Ionization energy Signup and view all the answers

From left to right across a period on the periodic table, electron affinity values tend to become more?

Negative Signup and view all the answers

From left to right across a period on the periodic table, ionization energy values tend to?

Increase Signup and view all the answers

From left to right across a period on the periodic table, atomic radii tend to become?

Smaller Signup and view all the answers

Name the halogen with the least-negative electron affinity.

At Signup and view all the answers

Name the alkali metal with the highest ionization energy.

Li Signup and view all the answers

Name the element in Period 3 with the smallest atomic radius.

Ar Signup and view all the answers

Name the Group 14 element with the largest electronegativity.

C Signup and view all the answers

Compare the radius of a positive ion to the radius of its neutral atom.

The radius of a positive ion is smaller than the radius of its corresponding neutral atom. Signup and view all the answers

Compare the radius of a negative ion to the radius of its neutral atom.

The radius of a negative ion is larger than the radius of its corresponding neutral atom. Signup and view all the answers

Give the approximate positions and blocks where metals and nonmetals are found in the periodic table.

Metals are on the left side of the periodic table, mostly in the s, d, and f blocks. Nonmetals are on the right side of the periodic table, all in the p block (except for hydrogen). Signup and view all the answers

Of metals and nonmetals, which tend to form positive ions? Which tend to form negative ions?

Metals tend to form positive ions; nonmetals tend to form negative ions. Signup and view all the answers

Explain why the second ionization energy is higher than the first, the third is higher than the second, and so on.

As electrons are removed in successive ionizations, fewer electrons remain within the atom to shield the attractive force of the nucleus. Each electron removed from an ion experiences a stronger effective nuclear pull than the electron removed before it. Signup and view all the answers

Explain the role of valence electrons in the formation of chemical compounds.

Valence electrons are the electrons most subject to the influence of nearby atoms or ions. They are the electrons available to be lost, gained, or shared in the formation of chemical compounds. Signup and view all the answers

Consider the neutral atom with 53 protons and 74 neutrons to answer the following questions. a. What is its atomic number? b. What is its mass number? c. Is the element's position in a modern periodic table determined by its atomic number or by its atomic mass?

53, 127, atomic number Signup and view all the answers

Consider an element whose outermost electron configuration is 3d10 4s2 4p x. a. To which period does the element belong? b. If it is a halogen, what is the value of x? c. The group number will equal (10 + 2 + x). True or False?

Period 4, 5, true Signup and view all the answers

A. In which block are metalloids found, s, p, d, or f? b. In which block are the hardest, densest metals found, s, p, or d?

p, d Signup and view all the answers

Name the most chemically active halogen.

Fluorine Signup and view all the answers

Which class has greater ionization energies, metals or nonmetals?

Nonmetals Signup and view all the answers

An element with a large negative electron affinity is most likely to form a?

Negative ion Signup and view all the answers

In general, which has a stronger electron attraction, a large atom or a small atom?

Small Signup and view all the answers

Who was credited with developing a method that led to the determination of standard relative atomic masses?

Cannizzaro Signup and view all the answers

Who created a table in which elements with similar properties were grouped together, and discovered the periodic law?

Mendeleev Signup and view all the answers

Who discovered that the elements fit into patterns better when they were arranged according to atomic number rather than atomic weight and established atomic numbers?

Mosley Signup and view all the answers

This states that the physical and chemical properties of the elements are periodic functions of their atomic numbers?

The periodic law Signup and view all the answers

What is an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column or group?

Modern periodic table Signup and view all the answers

Name three sets of elements that have been added to the periodic table since Mendeleev's time.

Noble gases, lanthanides, actinides Signup and view all the answers

The length of a period is determined by...?

The number of electrons that can occupy sub-levels being filled in that period. Signup and view all the answers

What are the 4 blocks?

s, p, d, f Signup and view all the answers

Noble gases are __________ in relation to reactivity.

Unreactive Signup and view all the answers

Group 1 elements, otherwise known as the _ are silvery and soft enough to cut with a knife?

Alkali metals Signup and view all the answers

Alkali metals are ___________ in relation to reactivity?

Very reactive Signup and view all the answers

Group 2 elements, otherwise known as _ ___ are less reactive, but still too reactive to be found in pure form?

Alkaline earth metals Signup and view all the answers

The d - block elements are metals with typical metallic properties and are often referred to as what?

Transition metals Signup and view all the answers

Groups 13-18 are the ___ block.

P Signup and view all the answers

Group 17 elements are the _________

Halogens Signup and view all the answers

The p-block elements together with the s - block elements are called the what?

Main-group elements Signup and view all the answers

What are the most reactive nonmetals?

Halogens Signup and view all the answers

What are wedged between Groups 3 and 4 in the sixth and seventh periods?

F-block elements Signup and view all the answers

The first row of f-block are?

Lanthanides Signup and view all the answers

The second row of f-block are?

Actinides Signup and view all the answers

Actinides are very __________.

Radioactive Signup and view all the answers

What are the group 18 elements?

Noble gases Signup and view all the answers

What is half the distance between the nuclei of identical atoms that are bonded together?

Atomic radius Signup and view all the answers

The farther to the right atomic radii are found across a period, the _________ the atom. This is caused by an increasing positive charge of the nucleus, which...?

Smaller, attracts electrons toward the nucleus. Signup and view all the answers

The atomic radii of the main-group elements ______________ down a group.

Increase Signup and view all the answers

An atom or group of bonded atoms that has a positive or negative charge.

Ion Signup and view all the answers

Any process that results in the formation of an ion.

Ionization Signup and view all the answers

The energy required to remove one electron from a neutral atom of an element is the...?

Ionization energy Signup and view all the answers

Ionization energy across a period, and ____ down a group.

Increases, decreases Signup and view all the answers

Each successive electron removed from an ion feels...?

An increasingly stronger effective nuclear charge Signup and view all the answers

The energy change that occurs when an electron is acquired by a neutral atom is called the atom's...

Electron affinity Signup and view all the answers

Electron affinity generally __ across a period, _ down a group.

Increases, decreases Signup and view all the answers

A positive ion is known as a...

Cation Signup and view all the answers

A negative ion is known as a...

Anion Signup and view all the answers

Formation of a cation by the loss of one or more electrons always leads to a ___________ in atomic radius?

Decrease Signup and view all the answers

Formation of an anion by the addition of one or more electrons always leads to an ____________ in atomic radius?

Increase Signup and view all the answers

There is a gradual increase of ionic radii where?

Down a group Signup and view all the answers

The electrons available to be lost, gained, or shared in the formation of chemical compounds are referred to as the what?

Valence electrons Signup and view all the answers

A measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound.

Electronegativity Signup and view all the answers

In the p-block, you calculate the number of valence electrons by doing what?

Group number - 10 Signup and view all the answers

Electronegativities tend to __________ across each period.

Increase Signup and view all the answers

Study Notes

The Periodic Law and Atomic Structure

Modern periodic table organizes elements by increasing atomic number.
Mendeleev observed similarities in chemical properties at regular intervals in terms of atomic mass.
Modern periodic law states element properties are functions of atomic number, not atomic mass.

Noble Gases and Element Groups

Discovery of noble gases added a new group to Mendeleev’s periodic table.
Noble gases, found in Group 18, are characterized by low reactivity.
Alkali metals (Group 1) are silvery, soft, and very reactive; alkaline earth metals (Group 2) are less reactive.

Atomic Structure and Isotopes

Isotopes are defined by mass number (protons + neutrons) and atomic number (protons).
Atomic number determines element identity; for fluorine, mass number is 19, atomic number is 9.

Periods, Groups, and Blocks in the Periodic Table

Elements belong to periods (horizontal rows) and groups (vertical columns) based on properties.
Different blocks: s (Groups 1-2), p (Groups 13-18), d (Groups 3-12), f (lanthanides and actinides).

Ionization Energy and Electron Affinity

Ionization energy requires energy to remove electrons; it increases across a period and decreases down a group.
Electron affinity measures the energy change when an electron is gained; it increases across a period and decreases down a group.

Atomic and Ionic Radii

Atomic radii decrease across a period due to increased nuclear charge attracting electrons closer.
Positive ions (cations) have smaller radii than their neutral atoms; negative ions (anions) have larger radii.

Valence Electrons and Chemical Reactivity

Valence electrons define an atom’s ability to form bonds, lost or gained during chemical reactions.
Electronegativity, the ability of an atom to attract electrons, tends to increase across a period.

Reactivity of Halogens and Nonmetals

Halogens (Group 17) are highly reactive nonmetals, with fluorine being the most reactive.
Nonmetals typically form negative ions while metals form positive ions.

Historical Figures and Contributions

Cannizzaro developed methods for standard atomic masses.
Mendeleev created tables grouping elements by properties and discovering periodic law.
Moseley determined elements fit better by atomic number rather than atomic weight.

Summary of Key Trends in the Periodic Table

Ionization energy increases with successive electron removal because of stronger effective nuclear charge.
The radius of positive ions is smaller; negative ions have a larger radius compared to their neutral counterparts.
Group 14 elements have varying electronegativities, with patterns observable in different periods and blocks of elements.

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Test your knowledge of Chapter 5 on The Periodic Law with these flashcards. This quiz covers key concepts such as the arrangement of elements in the periodic table and the observations made by Mendeleev. Challenge yourself to recall essential definitions and properties of elements.

Chemistry Chapter 5 - The Periodic Law

Questions and Answers

In the modern periodic table, elements are ordered according to which of these?

Mendeleev noticed that certain similarities in the chemical properties of elements appeared at regular intervals when the elements were arranged in order of increasing?

What does the modern periodic law state?

The discovery of the noble gases changed Mendeleev's periodic table by adding a new?

The most distinctive property of the noble gases is that they are?

Lithium, the first element in Group 1, has an atomic number of 3. The second element in this group has an atomic number of?

An isotope of fluorine has a mass number of 19 and an atomic number of 9. How many protons are in this atom?

An isotope of fluorine has a mass number of 19 and an atomic number of 9. How many neutrons are in this atom?

A certain isotope contains 53 protons, 78 neutrons, and 54 electrons. What is its atomic number?

A certain isotope contains 53 protons, 78 neutrons, and 54 electrons. What is the mass number of this atom?

A certain isotope contains 53 protons, 78 neutrons, and 54 electrons. What is the name of this element?

In a modern periodic table, every element is a member of both a horizontal row and a vertical column. Which one is the group, and which one is the period?

Explain the distinction between atomic mass and atomic number of an element.

There are 18 columns in the periodic table; each has a group number. Give the group numbers that make up each of the following blocks: s block, p block, d block.

When an electron is added to a neutral atom, energy is?

The energy required to remove an electron from a neutral atom is the atom's?

From left to right across a period on the periodic table, electron affinity values tend to become more?

From left to right across a period on the periodic table, ionization energy values tend to?

From left to right across a period on the periodic table, atomic radii tend to become?

Name the halogen with the least-negative electron affinity.

Name the alkali metal with the highest ionization energy.

Name the element in Period 3 with the smallest atomic radius.

Name the Group 14 element with the largest electronegativity.

Compare the radius of a positive ion to the radius of its neutral atom.

Compare the radius of a negative ion to the radius of its neutral atom.

Give the approximate positions and blocks where metals and nonmetals are found in the periodic table.

Of metals and nonmetals, which tend to form positive ions? Which tend to form negative ions?

Explain why the second ionization energy is higher than the first, the third is higher than the second, and so on.

Explain the role of valence electrons in the formation of chemical compounds.

Consider the neutral atom with 53 protons and 74 neutrons to answer the following questions. a. What is its atomic number? b. What is its mass number? c. Is the element's position in a modern periodic table determined by its atomic number or by its atomic mass?

Consider an element whose outermost electron configuration is 3d10 4s2 4p x. a. To which period does the element belong? b. If it is a halogen, what is the value of x? c. The group number will equal (10 + 2 + x). True or False?

A. In which block are metalloids found, s, p, d, or f? b. In which block are the hardest, densest metals found, s, p, or d?

Name the most chemically active halogen.

Which class has greater ionization energies, metals or nonmetals?

An element with a large negative electron affinity is most likely to form a?

In general, which has a stronger electron attraction, a large atom or a small atom?

Who was credited with developing a method that led to the determination of standard relative atomic masses?

Who created a table in which elements with similar properties were grouped together, and discovered the periodic law?

Who discovered that the elements fit into patterns better when they were arranged according to atomic number rather than atomic weight and established atomic numbers?

This states that the physical and chemical properties of the elements are periodic functions of their atomic numbers?

What is an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column or group?

Name three sets of elements that have been added to the periodic table since Mendeleev's time.

The length of a period is determined by...?

What are the 4 blocks?

Noble gases are __________ in relation to reactivity.

Group 1 elements, otherwise known as the ________ _________ are silvery and soft enough to cut with a knife?

Alkali metals are ___________ in relation to reactivity?

Group 2 elements, otherwise known as _______ ________ _________ are less reactive, but still too reactive to be found in pure form?

The d - block elements are metals with typical metallic properties and are often referred to as what?

Groups 13-18 are the ___ block.

Group 17 elements are the _________

The p-block elements together with the s - block elements are called the what?

What are the most reactive nonmetals?

What are wedged between Groups 3 and 4 in the sixth and seventh periods?

The first row of f-block are?

The second row of f-block are?

Actinides are very __________.

What are the group 18 elements?

What is half the distance between the nuclei of identical atoms that are bonded together?

The farther to the right atomic radii are found across a period, the _________ the atom. This is caused by an increasing positive charge of the nucleus, which...?

The atomic radii of the main-group elements ______________ down a group.

An atom or group of bonded atoms that has a positive or negative charge.

Any process that results in the formation of an ion.

The energy required to remove one electron from a neutral atom of an element is the...?

Ionization energy ______ across a period, and __________ down a group.

Each successive electron removed from an ion feels...?

The energy change that occurs when an electron is acquired by a neutral atom is called the atom's...

Electron affinity generally __________ across a period, _________ down a group.

A positive ion is known as a...

A negative ion is known as a...

Formation of a cation by the loss of one or more electrons always leads to a ___________ in atomic radius?

Formation of an anion by the addition of one or more electrons always leads to an ____________ in atomic radius?

There is a gradual increase of ionic radii where?

The electrons available to be lost, gained, or shared in the formation of chemical compounds are referred to as the what?

A measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound.

In the p-block, you calculate the number of valence electrons by doing what?

Electronegativities tend to __________ across each period.

Study Notes

Group 1 elements, otherwise known as the _ are silvery and soft enough to cut with a knife?

Group 2 elements, otherwise known as _ ___ are less reactive, but still too reactive to be found in pure form?

Ionization energy across a period, and ____ down a group.

Electron affinity generally __ across a period, _ down a group.