Periodic Table Organization and Classification

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Questions and Answers

What is the definition of the periodic law?

A set of rules for classifying elements as metals or nonmetals.

A periodic repetition of chemical and physical properties of elements arranged by increasing atomic number. (correct)

A periodic repetition of chemical and physical properties of elements arranged by atomic mass.

A description of the physical states of elements at room temperature.

Which elements are classified as alkali metals?

Elements in group 1, excluding hydrogen. (correct)

Elements in group 18.

Elements in group 3-12.

Elements in group 2.

What did Henry Moseley contribute to the periodic table?

He organized elements by increasing atomic number. (correct)

He categorized elements based on their physical states.

He introduced the concept of groups and periods.

He arranged elements by increasing atomic mass.

What are representative elements?

Elements in groups 1, 2, and 13-18. Signup and view all the answers

What are metalloids known for?

Having properties of both metals and nonmetals. Signup and view all the answers

Which group contains noble gases?

Group 18. Signup and view all the answers

What characteristic is shared by all transition metals?

They possess similar chemical properties. Signup and view all the answers

What defines the groups in the periodic table?

They are columns of elements with similar properties. Signup and view all the answers

Which of the following statements about alkali metals is true?

They are solid at room temperature and highly reactive. Signup and view all the answers

What defines the periodic trend of atomic radius across a period?

Atomic radius decreases from left to right. Signup and view all the answers

Which group contains elements that are known as noble gases?

Group 18 Signup and view all the answers

What is true about the ionization energy as you move down a group in the periodic table?

Ionization energy decreases. Signup and view all the answers

What happens to an atom when it loses electrons?

It becomes a positively charged ion and its radius decreases. Signup and view all the answers

Which type of elements have properties of both metals and nonmetals?

Metalloids Signup and view all the answers

How are the elements classified into blocks on the periodic table?

Based on their electron configuration. Signup and view all the answers

What is the octet rule in chemistry?

Atoms tend to gain, lose, or share electrons to have eight valence electrons. Signup and view all the answers

Which statement best describes electronegativity trends in the periodic table?

Electronegativity increases from left to right across a period. Signup and view all the answers

What characteristic do transition metals typically exhibit?

They have filled or partially filled d orbitals. Signup and view all the answers

Study Notes

Periodic Table Organization and Classification

Periodic law: Chemical and physical properties repeat periodically as atomic number increases.
Groups (families): Vertical columns; elements have similar properties.
Periods: Horizontal rows; elements' properties change gradually.
Representative elements: Groups 1, 2, and 13-18; diverse properties.
Transition metals: Groups 3-12; often good conductors.
Metals: Shiny, solid at room temp, good conductors of heat/electricity.
Alkali metals: Group 1 (except H); highly reactive.
Alkaline earth metals: Group 2; also reactive.
Transition and inner transition metals: Subsections within the transition metals.
Lanthanide and Actinide series: Inner transition metals (bottom rows).
Nonmetals: Gases or brittle solids, poor conductors.
Halogens: Group 17; highly reactive.
Noble gases: Group 18; extremely unreactive.
Metalloids: Properties of both metals and nonmetals.

Historical Development of the Periodic Table

Lavoisier: Compiled a list of known elements in the late 1700's.
New discoveries in the 1800s spurred the need for organization.
Newlands: Arranged elements by atomic mass, noticed 8 element pattern.
Mendeleev: Created an early periodic table, organized by atomic mass and properties; predicted undiscovered elements.
Moseley: Refined Mendeleev's table, arranging elements by atomic number; resulted in a clear, periodic pattern.

Modern Periodic Table

Contains Name, Symbol, Atomic Number, and Atomic Mass for each element.
Columns are called groups or families.
Rows are called periods.

Element Classification

Elements are broadly classified as metals, nonmetals, and metalloids.

Electron Configuration and Periodic Table Structure

Electron configurations determine chemical properties.
Valence electrons: Electrons in the outermost energy level. Relates to element position on PT.
Group 1: 1 valence electron
Group 2: 2 valence electrons
Groups 13-18: Valence electrons = group number - 10
Energy levels of valence electrons correspond to the period of the element.
Blocks (s, p, d, f) correspond to filled/partially filled energy sublevels.
S-block: Groups 1 & 2 (plus He).
P-block: Groups 13-18
D-block: Transition metals (largest block). They have filled outermost s orbitals & filled/partially filled d orbitals.
F-block: Inner transition metals (lanthanides & actinides). Filled outermost s orbitals & filled/partially filled 4f or 5f orbitals.

Periodic Trends: Atomic Size

Atomic radius decreases left-to-right across a period.
Atomic radius increases down a group.
Metallic atomic radius = half distance between adjacent atoms in a crystal lattice.

Periodic Trends: Ionization Energy and Electronegativity

Ionization energy: Energy to remove an electron. Increases left-to-right, decreases down a group.
First ionization energy: Energy to remove the first electron.
Successive ionization energies: Increasing by each removal.
Octet rule: Atoms tend to gain/lose/share electrons to achieve 8 valence electrons (exceptions occur).
Electronegativity: Ability of an atom to attract electrons in a bond. Increases left-to-right, decreases down a group.

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Description

Test your knowledge on the organization and classification of the periodic table. This quiz covers periodic law, groups, periods, and the various classes of elements including metals, nonmetals, and metalloids. Understand the characteristics of different groups and their historical development.