Group 14 and 15 Elements Quiz

The increase in nuclear charge outweighs the shielding effect from the additional 4f- and 5d-electrons.

Group 14 elements generally have high melting and boiling points.

Carbon's anomalous behavior is due to its small atomic size, higher ionization enthalpy, absence of d-orbitals, and higher electronegativity.

<p>The order of catenation is C &gt; Si &gt; Ge ≈ Sn &gt; Pb.</p> Signup and view all the answers

<p>D-orbitals allow heavier elements to expand their covalence, unlike carbon, which can only accommodate four pairs of electrons.</p> Signup and view all the answers

<p>Lead is stable in the +2 oxidation state, while its +4 oxidation state serves as a strong oxidizing agent.</p> Signup and view all the answers

<p>Group 14 elements form both monoxide (MO) and dioxide (MO₂) oxides.</p> Signup and view all the answers

<p>Dioxides in higher oxidation states are generally more acidic than those in lower oxidation states.</p> Signup and view all the answers

<p>The metallic character increases down Group 15 due to decreasing ionization enthalpy and increasing atomic size.</p> Signup and view all the answers

<p>Electronegativity decreases down the group as atomic size increases, making it harder for larger atoms to attract electrons.</p> Signup and view all the answers

<p>Nitrogen's anomalous properties are due to its small size, high electronegativity, high ionization enthalpy, and the lack of available d orbitals.</p> Signup and view all the answers

<p>The atomic radius of gallium is smaller than that of aluminum due to the presence of poor shielding by the 10d-electrons, which results in a higher effective nuclear charge.</p> Signup and view all the answers

<p>Group 15 elements form hydrides of the type $EH_3$ which show decreasing stability from $NH_3$ to $BiH_3$ due to increasing atomic size and decreasing bond dissociation enthalpy.</p> Signup and view all the answers

<p>Melting points increase from nitrogen to arsenic and then decrease for bismuth due to changes in atomic structure and bonding.</p> Signup and view all the answers

<p>The first ionization enthalpies of group 13 elements are lower because it is easier to remove a p-electron compared to an s-electron, making ionization less energy-intensive.</p> Signup and view all the answers

<p>The maximum covalency of oxygen is four, but it rarely exceeds two due to the absence of d orbitals in its valence shell.</p> Signup and view all the answers

<p>The N-N bond length is shorter and stronger than the P-P bond due to higher interelectronic repulsion in nitrogen.</p> Signup and view all the answers

<p>The acidic character increases from $H_2O$ to $H_2Te$ due to a decrease in bond dissociation enthalpy.</p> Signup and view all the answers

<p>As one moves down group 13, the first ionization enthalpies decrease due to an increase in atomic size and screening effects, which outweigh the nuclear charge increase.</p> Signup and view all the answers

<p>Ionization enthalpy decreases down the group due to the increase in atomic size and shielding effect.</p> Signup and view all the answers

<p>The electronegativity in group 13 decreases from boron to aluminum due to increased atomic size, before it starts increasing again as we move down the group.</p> Signup and view all the answers

<p>The reducing property of the dioxides decreases from $SO_2$ to $TeO_2$, indicating that $SO_2$ is a stronger reducing agent.</p> Signup and view all the answers

<p>The elements form halides of types $EX_6$, $EX_4$, and $EX_2$, with hexafluorides being the most stable.</p> Signup and view all the answers

<p>Boron has a high melting point due to its strong crystalline lattice structure, while other group 13 members have low melting points due to their metallic nature.</p> Signup and view all the answers

<p>Heavier elements do not form pn-pn bonds because their atomic orbitals are large and diffuse, preventing effective overlap.</p> Signup and view all the answers

<p>Boron and aluminum typically show a +3 oxidation state, while gallium, indium, and thallium can exhibit both +1 and +3 oxidation states, with +1 stability increasing down the group.</p> Signup and view all the answers

<p>The reaction is $4Al + 3O_2 ightarrow 2Al_2O_3$, which forms aluminum oxide, a crucial insulating material.</p> Signup and view all the answers

<p>The atomic radii of halogens increase down the group, from fluorine to astatine, due to the addition of electron shells.</p> Signup and view all the answers

<p>Boron does not react with oxygen in its crystalline form, whereas aluminum, despite being thermodynamically reactive, forms a protective layer that inhibits further reaction.</p> Signup and view all the answers

<p>When heated, group 13 elements react with oxygen to form trioxides, $M_2O_3$, with boron forming $B_2O_3$ only in its amorphous state.</p> Signup and view all the answers

<p>Iodine has the electronic configuration of [Kr] $4d^{10} 5s^2 5p^5$, allowing it to readily accept an electron to achieve stability.</p> Signup and view all the answers

<p>The thermal stability decreases as the bond dissociation enthalpy of the hydrides decreases from $H_2O$ to $H_2Te$.</p> Signup and view all the answers

<p>The increase in atomic and ionic radii down the group is due to the increasing number of quantum shells.</p> Signup and view all the answers

<p>Ionization enthalpy decreases down the group due to the increase in atomic size.</p> Signup and view all the answers

<p>Fluorine's smaller size leads to strong interelectronic repulsions in its 2p orbitals, reducing its electron gain enthalpy.</p> Signup and view all the answers

<p>Melting and boiling points increase with atomic number among halogens.</p> Signup and view all the answers

<p>The order is $Cl_2 &gt; Br_2 &gt; F_2 &gt; I_2$.</p> Signup and view all the answers

<p>Chlorine, bromine, and iodine can exhibit +1, +3, +5, and +7 oxidation states.</p> Signup and view all the answers

<p>The acidic strength increases from HF to HI, following the order HF &lt; HCl &lt; HBr &lt; HI.</p> Signup and view all the answers

<p>Fluorine's anomalous behavior is attributed to its small size and higher ionization enthalpy, electronegativity, and the absence of d orbitals in its valence shell.</p> Signup and view all the answers

<p>The basicity of hydrides $MH_3$ decreases down the group: $NH_3 &gt; PH_3 &gt; AsH_3 &gt; SbH_3 &gt; BiH_3$, due to the increasing size of the central atom which reduces electron density.</p> Signup and view all the answers

<p>The thermal stability decreases down the group: $NH_3 &gt; PH_3 &gt; AsH_3 &gt; SbH_3 &gt; BiH_3$, because the larger central atoms form weaker M-H bonds.</p> Signup and view all the answers

<p>The melting and boiling points generally increase down the group, except for $NH_3$, due to increasing van der Waals forces.</p> Signup and view all the answers

<p>The oxide in the higher oxidation state ($E_2O_5$) is more acidic than its lower oxidation state counterpart ($E_2O_3$), and acidic character decreases down the group.</p> Signup and view all the answers

<p>They form trihalides ($MX_3$) and pentahalides ($MX_5$), with all trihalides (except $BiF_3$) being predominantly covalent and stable.</p> Signup and view all the answers

<p>Reducing character of hydrides increases down the group, as their stability decreases leading to greater reducing ability.</p> Signup and view all the answers

<p>Chalcogens, derived from Greek meaning 'ore forming,' refers to elements like oxygen and sulfur, which are associated with copper minerals.</p> Signup and view all the answers

<p>Nitrogen does not form pentahalides due to the absence of available d orbitals, which restricts its ability to form stable $MX_5$ compounds.</p> Signup and view all the answers