Classification of Elements and Periodicity in Properties

The root word 'bi' in IUPAC naming represents which digit?

Which block of the periodic table contains the most reactive metals?

Which period contains 18 elements?

The IUPAC name for $Z = 112$ is:

Identify the IUPAC name for the element with atomic number 110.

The element with atomic number $Z = 55$ belongs to which block and period?

The general valence shell electronic configuration of $p$-block elements is:

The number of elements in the second and third periods is 8 each. This is because the maximum number of electrons that can be accommodated in the valence shell of these elements is:

Identify the element having the highest atomic number among the following, which is not a transuranic element.

An element belongs to Group 15 and Period 4. What is its electronic configuration?

What is the atomic number of the element placed in Period 2 and Group 14?

To which group does an element with the configuration $ns^2 np^6$ belong?

The d-block elements are also known as:

Which of the following is the electronic configuration of Calcium ($Z=20$)?

The element with atomic number $Z=52$ (Tellurium) belongs to which group?

What is the maximum number of elements that can be accommodated in the $s, p, d$ and $f$ blocks of a single period?

Which of the following elements is a $d$-block element but NOT a transition element according to the strict definition?

Which of the following is the correct quantum number set for the last electron added to the element Rubidium ($Z=37$)?

Identify the element that has the highest ratio of unpaired electrons to the total number of electrons in its $3d$ subshell.

An element $Y$ has the outer configuration $5s^2 5p^2$. Which of the following is true about this element?

Which property of an element is most closely related to its chemical reactivity?

Across the 2nd period, as atomic number increases, the atomic radius generally:

Which of the following elements belongs to the 4th period?

The maximum oxidation state of an element in the p-block is usually equal to:

Using the Pauling scale of electronegativity (where $B \approx 2.0, C \approx 2.5, N \approx 3.0, O \approx 3.5, F \approx 4.0, H \approx 2.1$), which of the following covalent bonds would be expected to have the highest degree of polarity (largest dipole character)?

The oxides of the third-period elements exhibit a distinct trend in their chemical nature from left to right. Which of the following sequences correctly identifies the transition in the nature of oxides for $Na, Mg, Al, Si, P, S,$ and $Cl$?

Considering the successive ionization enthalpies ($IE_1, IE_2, IE_3$) of Magnesium ($Z=12$) and Aluminum ($Z=13$), which of the following statements correctly compares their third ionization enthalpy ($IE_3$)?

Which of the following is the most electronegative element in the fourth period?

Across the second period from $Li$ to $F$, which property shows a non-monotonic (irregular) trend?

The correct order of increasing electron gain enthalpy (with negative sign) for $O, S, F$ and $Cl$ is:

As we move across the 4th period from $K$ to $Kr$, what is the general trend in atomic radius?

Which of the following atoms has the highest effective nuclear charge ($Z_{eff}$) for its valence electrons in Period 3?

Which of the following ions is the largest in size?

The measurement of the distance between nuclei in a crystal is generally done using:

Among $Cl, S$, and $P$, the order of increasing atomic radii is:

What happens to the radius of an atom when it loses its outermost shell entirely during cation formation (e.g., $Na$ to $Na^{+}$)?

In the comparison between $d$ and $f$ electron shielding, $f$ electrons provide:

A plot of metallic radii against atomic number for the $3d$ transition series shows that the radius decreases from Scandium to Chromium, remains relatively constant until Nickel, and then shows a distinct increase from Copper ($128\text{ pm}$) to Zinc ($137\text{ pm}$). Which of the following statements provides the best scientific explanation for the increase in the atomic radius of Zinc compared to Copper?

In the $d$-block, the 'Lanthanoid contraction' explains why the second ($4d$) and third ($5d$) transition series elements have very similar atomic radii. However, this similarity is not observed between Yttrium ($Y, Z=39$) and Lanthanum ($La, Z=57$), where a normal increase in radius occurs. Why is the effect of the Lanthanoid contraction not seen in the transition from Yttrium to Lanthanum?

Which among the following is the correct order of the size of $3d$ series elements?

Which of the following ions is isoelectronic with $Ne$?

In the comparison between $Cu^+$ and $Cu^{2+}$, which ion is smaller?

Which of the following has the smallest ionic radius?

What is the relationship between the number of protons and ionic radius for isoelectronic species?

Which of the following ions has the largest radius among $N^{3-}, P^{3-}, As^{3-}$?

Among $O^{2-}, F^-, Na^+, Mg^{2+}$, which has the highest ratio of nuclear charge to electrons?

Which of the following represents the correct trend for Group 13 ionic radii?

The radii of $F^-$ and $O^{2-}$ are $1.33$ Å and $1.40$ Å respectively, while the radius of $N^{3-}$ is $1.71$ Å. This significant increase in size for $N^{3-}$ is due to:

What is the primary reason the ionic radius of $Cu^+$ ($0.96$ Å) is larger than $Cu^{2+}$ ($0.73$ Å)?

For the ions $Te^{2-}, I^-, Cs^+, Ba^{2+}$, what is the correct order of decreasing ionic radii?

Removal of an electron from which of the following species would require the most energy?

Which of the following is true for an isolated gaseous atom?

Across the second period, the general trend of ionization enthalpy is:

If an atom has a very low ionization enthalpy, it is most likely to be a:

The second ionization enthalpy of Chromium ($Z=24$) is higher than that of Manganese ($Z=25$). This is because:

Why does the ionization enthalpy increase from left to right in a period?

Among the following isoelectronic species, which one has the highest ionization enthalpy?

In the periodic table, Group 15 elements generally exhibit higher first ionization enthalpies ($IE_1$) than Group 16 elements in the same period due to their stable half-filled ($np^3$) electronic configuration. However, the magnitude of the difference ($\Delta IE = IE_{\text{Group 15}} - IE_{\text{Group 16}}$) decreases significantly as we move from Period 2 to Period 4, as shown in the diagram. Which of the following statements provides the most accurate scientific explanation for this trend?

Arrange the following species in decreasing order of their second ionization enthalpy: $Li, Be, B, C$.

Consider the following sequences of elements. In which sequence do the ionization enthalpies NOT strictly increase?

Which of the following elements will release the most energy when a gaseous atom accepts an electron?

Which physical state of an atom is required to measure its electron gain enthalpy standardly?

As we move from Na to Cl in the third period, the electron gain enthalpy generally:

Which of the following is correct for the first electron gain enthalpy of Nitrogen?

Which of the following is true regarding the electron gain enthalpy of Group 2 elements?

Which of the following elements has the lowest tendency to form a uninegative ion in the gaseous state?

In the general trend, the electron gain enthalpy becomes less negative from $S$ to $Te$ in Group 16. What is the reason?

Which statement accurately describes the comparison between $O$ and $F$ electron gain enthalpies?

An element $M$ has a very high first ionization enthalpy and a positive electron gain enthalpy. $M$ is likely to be:

In the process $X(g) + e^- \rightarrow X^-(g)$, if $\Delta H = -3.5 \text{ eV}$, what is the electron affinity of $X$ in eV?

Which of the following elements has an electronegativity of 2.5 on the Pauling scale?

As the positive charge on a cation increases, its electronegativity:

In the periodic table, diagonal relationships exist. Which element has an electronegativity close to that of Aluminium ($1.5$)?

What is the electronegativity of Oxygen on the Pauling scale approximately?

In the molecule $CH_3Cl$, the direction of the bond dipole for the $C-Cl$ bond is:

The electronegativity of $N$ ($3.0$) and $Cl$ ($3.0$) are identical on the Pauling scale. However, Nitrogen can form hydrogen bonds while Chlorine generally does not. This is primarily because:

Which of the following trends is NOT correct regarding electronegativity?

The electronegativity of an atom in a molecule can be influenced by the inductive effect of neighboring groups. Which of the following groups will increase the effective electronegativity of a Carbon atom to which it is attached?

Which of the following scales of electronegativity is considered a 'dimensionless' quantity?

Among the following, which element has the lowest electronegativity?

Which of these classifications was the first to consider atomic weight as a base for periodicity?

Why is Hydrogen's position often discussed as a special case in the classification of elements?

Classification allows chemists to predict the formula of:

Most of the recently discovered elements (Atomic Number > 94) are:

Which of the following best summarizes the 'need for classification' in chemistry?

Classification is useful for predicting the maximum valency of an element based on its:

The development of classification showed that the properties of elements are a result of their:

Consider the logic: 'If elements are arranged in increasing order of atomic masses, the properties of elements repeat'. This logic was the basis of classification for nearly 50 years. Which element's position in the table was the most controversial 'exception' to this mass-based rule before Moseley's work?

Mendeleev's table had 8 groups. Group VIII was unique because it contained 'Triads' of elements like $Fe, Co, Ni$. What was the purpose of this specific arrangement?

In the early 1800s, classification was difficult because many elements were not 'pure'. Which discovery was most important in allowing chemists to isolate elements and thus classify them correctly?

Which of the following was the main achievement of Mendeleev's classification?

Mendeleev corrected the valency of which element from 3 to 2?

The position of which element was not fixed in Mendeleev's periodic table?

Before Mendeleev, who else published a nearly identical periodic table in the same year (1869)?

Which of the following scientists is known as the 'Father of the Periodic Table'?

In Lothar Meyer's atomic volume curve, the transition elements occupy:

The horizontal rows in the modern periodic table were originally referred to as 'series' in Mendeleev's terminology. How many such periods were there in his original 1871 table?

Which of the following was NOT one of the 63 elements known at the time of Mendeleev's first classification?

The failure of Mendeleev's periodic table to explain the position of isotopes is because:

Dmitri Mendeleev used 'Eka-Boron' to describe a gap. When Scandium was discovered, its properties were found to be very similar. What does the prefix 'Eka' mean in this context?

Based on the systematic IUPAC nomenclature process shown in the diagram for element $Z = 132$, which rule is used to derive the three-letter symbol from the numerical roots?

How many letters are there in the systematic IUPAC symbol for elements with $Z > 100$?

The element with the symbol 'Uus' has which atomic number?

What is the atomic number of the element with the symbol 'Unp'?

The element 'Unununnium' corresponds to $Z$ equal to:

What is the correct root for digit 2?

The root 'nil' is derived from which language/source in this context?

How many 'i' letters are present in the systematic name of element $102$?

What is the symbol for an element with atomic number $113$?

Which of the following elements has the systematic name 'Unnilquadium'?

Which of the following is a metalloid?

The valence shell electronic configuration of Halogens is:

Which of the following elements belongs to the f-block?

The IUPAC symbol for the element with atomic number 115 is:

The periodic table is divided into blocks based on the orbital being filled. Which block is unique because it is the only one that contains a diverse mixture of metals, non-metals, and metalloids as represented in the classification diagram?

In the $3d$ transition series, the atomic radii do not follow a simple decreasing trend. As shown in the conceptual balance below, why does the atomic radius remain nearly constant for elements in the middle of the series (from $Mn$ to $Ni$)?

The successive ionization enthalpies ($IE_1, IE_2, IE_3, IE_4$) of a third-period element are given in the diagram. Based on the significant jump in energy required to remove the fourth electron, which group does this element belong to?

Which of the following $p$-block elements does not show the 'Inert Pair Effect'?

If the electronegativity of an element is 2.5 and that of another element is 4.0, the bond formed between them will be:

Which of the following represents the correct order of the first ionization enthalpy of $O, S, Se, Te$?