Periodic Table and Periodicity Practice Quiz (7 questions)

1. A student uses the periodic table to classify an element and predict its behavior. Which statements describe features that support this task?

A. The four blocks are named s, p, d, and f, and represent four horizontal periods.

B. The table is generally divided into the s, p, d, and f blocks.

C. Le tableau est généralement divisé en blocs s, p, d et g.

D. Its organization helps explain trends in electronegativity, atomic radius, and ionization energy.

E. Its organization explains trends in electronegativity, atomic mass, and melting point.

Answer: (B), (D)

Explanation

Le tableau est généralement divisé en blocs s, p, d et f, et son organisation aide à expliquer des tendances comme l’électronégativité, le rayon atomique et l’énergie d’ionisation. Le bloc g ne fait pas partie des quatre blocs, et la masse atomique et le point de fusion ne sont pas les tendances citées ici. Les blocs ne désignent pas des périodes horizontales.

2. Which statements correctly identify Moseley's contribution to periodic classification?

A. Moseley a rangé les 63 éléments connus à l’époque selon leurs masses atomiques croissantes.

B. In 1913, Moseley established valence-electron count as the key classification criterion.

C. In 1913, Moseley discovered atomic number Z, establishing it as a key classification criterion.

D. In 1913, Moseley identified electron-shell count as the key classification criterion.

E. In 1913, Moseley established atomic mass as the key classification criterion.

Answer: (C)

Explanation

En 1913, Moseley a découvert le numéro atomique Z, qui est devenu le critère le plus important de la classification périodique. Le classement des 63 éléments connus selon leurs masses atomiques croissantes est associé à Mendeleïev, tandis que la masse atomique, le nombre de couches et le nombre d’électrons de valence ne sont pas le critère que Moseley a établi.

3. An element has atomic number 16 and is being located within the third period. Which statements apply?

A. The 3s and 3p subshells fill progressively across the third period.

B. The third period extends from sodium, atomic number 11, through argon, atomic number 18.

C. The element with atomic number 16 lies within the third-period range.

D. The 3s and 3p subshells fill progressively across the second period.

E. The third period begins with magnesium and ends with argon, atomic number 18.

Answer: (A), (B), (C)

Explanation

The 3s and 3p subshells fill progressively across the third period, which extends from sodium (Z = 11) to argon (Z = 18). An element with atomic number 16 lies within that range. The 3s and 3p subshells do not describe the progressive filling across the fourth period, and the third period begins with sodium, not magnesium.

4. A student uses the periodic table to infer bonding behavior from an element’s column. Which statements are correct?

A. A group is identified by a shared number of peripheral-shell electrons and a Roman numeral.

B. Elements in the same row have the same number of protons in their atoms.

C. Valence electrons occupy the innermost shell and determine an element’s bonding behavior.

D. Elements in one column have the same number of electrons in their outermost shell.

E. Valence electrons occupy the outermost shell and contribute to an element’s chemical properties.

Answer: (A), (D), (E)

Explanation

Elements in the same column have the same number of electrons in their outermost shell. These outermost-shell electrons are valence electrons that contribute to chemical properties, including bonding. A group is a set of elements with the same number of peripheral-shell electrons and is designated by a Roman numeral corresponding to that number. Elements in the same row do not have the same number of protons, and valence electrons occupy the outermost, not the innermost, shell.

5. A student compares the periodic-table group structure and its A subgroup. Which statements are accurate?

A. Subgroup A comprises eight families ordered by filling of the penultimate shell.

B. Groups are divided into two subgroups, designated A and B.

C. The table has 16 element families across 18 columns because group VIII B spans three columns.

D. Subgroup A has eight families arranged by progressive filling of the inner shell.

E. Subgroup A contains metals, nonmetals, and noble gases, arranged in eight families.

Answer: (B), (C), (E)

Explanation

Groups are subdivided into A and B, and the three-column span of group VIII B accounts for 16 families in 18 columns. Subgroup A includes metals, nonmetals, and noble gases in eight families arranged according to progressive filling of the peripheral shell; the families are not ordered by filling of the penultimate shell.

6. Regarding Dimitri Mendeleev’s early periodic classification:

A. Mendeleev proposed an early form of the periodic table.

B. Mendeleev arranged the 63 elements known in his time by increasing atomic mass.

C. Mendeleev’s early classification included 63 elements known during his lifetime.

D. Mendeleev’s early classification arranged the known elements by decreasing atomic mass.

E. Mendeleev arranged the elements known in his time by increasing atomic number.

Answer: (A), (B), (C)

Explanation

Mendeleev arranged the 63 then-known elements in increasing atomic-mass order and proposed an early periodic table. The historical ordering was not by atomic number or decreasing atomic mass.

7. A student traces the transition-element series in period seven. Which statements correctly characterize the actinides and their relationship to the rare earth subgroup?

A. The lanthanides, scandium, and yttrium together constitute the rare earths.

B. Progressive filling of the 5f subshell characterizes the actinide series in period seven.

C. The actinide series contains 14 transition elements following actinium, whose atomic number is 89.

D. Similar chemical properties make the subgroup C elements difficult to separate.

E. The lanthanides and actinides form subgroup C in the periodic-table classification.

Answer: (A), (B), (C), (D), (E)

Explanation

The 14 actinides follow actinium (Z = 89), and their formation involves progressive filling of the 5f subshell. The lanthanides and actinides form subgroup C and are difficult to separate because of their similar chemical properties; the broader rare-earth grouping also includes scandium and yttrium.