Question

Let E be any representative element. Following the pattern in the table, write formulas for the hydrogen and oxygen compounds of the following: (a) \(\mathrm{Na}\) (c) \(\mathrm{Al}\) (b) \(\mathrm{Ca}\) (d) \(\mathrm{Sn}\) $$ \begin{array}{|c|c|c|c|c|c|c|} \hline \text { Group } \\ \hline \mathbf{1 A ( 1 )} & \mathbf{2 A ( 2 )} & \mathbf{3 A ( 1 3 )} & \mathbf{4 A ( 1 4 )} & \mathbf{5 A ( 1 5 )} & \mathbf{6 A ( 1 6 )} & \mathbf{7 A ( 1 7 )} \\ \hline \mathrm{EH} & \mathrm{EH}_{2} & \mathrm{EH}_{3} & \mathrm{EH}_{4} & \mathrm{EH}_{3} & \mathrm{H}_{2} \mathrm{E} & \mathrm{HE} \\ \hline \mathrm{E}_{2} \mathrm{O} & \mathrm{EO} & \mathrm{E}_{2} \mathrm{O}_{3} & \mathrm{EO}_{2} & \mathrm{E}_{2} \mathrm{O}_{5} & \mathrm{EO}_{3} & \mathrm{E}_{2} \mathrm{O}_{7} \\ \hline \end{array} $$

Short answer

(a) NaH, Na2O; (b) CaH2, CaO; (c) AlH3, Al2O3; (d) SnH4, SnO2

Step-by-step solution

Identify Group Placement

Look at the periodic table and identify which group (column) each of the elements falls into. This information will help determine the subscript numbers in their compounds.

Deduce the Hydrogen Compound Formula

Using the group number from Step 1, write the formula of the hydrogen compound for each element by following the pattern in the table. The group number corresponds to the number of hydrogen atoms that will bond with the element.

Deduce the Oxygen Compound Formula

Similarly, determine the formula for each element's oxygen compound using the group number and the pattern given in the table. The group number relates to the pattern in which oxygen atoms bond with the element in the compound.

Write Down the Formulas

Write down the formulas based on the patterns for the hydrogen and oxygen compounds for each element following the trends in the given table.

Key concepts

Representative Elements

Representative elements are those which belong to the 's' or 'p' blocks of the periodic table. These are the elements in groups 1A to 7A (1, 2, and 13 to 17). A distinctive feature of these elements is that they have their outermost 's' or 'p' electron shells partially filled with electrons, and this configuration determines their properties and reactivity.

When looking at the representative elements, it is essential to understand that the group number can give us valuable information about the element's valency, which is a measure of its ability to combine with other atoms. The valency typically corresponds to the number of electrons the element needs to gain or lose to achieve a stable electron configuration, often resembling the nearest noble gas.

In an educational context, connecting the position of an element in the periodic table to its chemical behavior aids in forming a comprehensive understanding of how elements interact to form compounds. For instance, a systematic approach to formulating compounds with hydrogen and oxygen, as given in the aforementioned textbook exercise, can be easily comprehended through the study of these elements and their group properties.

Chemical Bonding

Chemical bonding is the process by which atoms combine to form new substances. Atoms can bond together in several ways, mainly through ionic, covalent, and metallic bonds. The type of bond formed depends on the elements involved and their electron configurations.

Ionic bonding occurs between metals and nonmetals, where one atom donates an electron to another, resulting in positively and negatively charged ions that are held together by electrostatic forces. Covalent bonding, on the other hand, happens when two nonmetals share electrons to obtain stability, and this sharing can be equal or unequal, leading to nonpolar or polar covalent bonds. Metallic bonding is a sea of electrons flowing around metal cations.

The pattern provided in the textbook exercise shows the formulas of hydrogen and oxygen compounds formed with representative elements, evidencing how these elements bond with hydrogen and oxygen. Understanding the fundamentals of chemical bonding is crucial for predicting how and why elements come together to form specific compounds, such as the hydrides (compounds with hydrogen) like \(\mathrm{EH_x}\), and oxides like \(\mathrm{EO_y}\) or \(\mathrm{E_xO_y}\), where E stands for a representative element.

Periodic Table Groups

The periodic table is organized into columns known as groups or families. Each group contains elements with similar physical and chemical properties because they have the same number of valence electrons. These shared characteristics make the periodic table a powerful tool in predicting the behavior of elements and their compounds.

Groups are numbered from 1 to 18 under the IUPAC system, where the groups 1A to 7A (1, 2, and 13 to 17) describe the representative elements. Group numbers can aid in the determination of formulas for compounds as they often reflect the number of bonds the elements can form with atoms of other elements. For example, group 1A elements (alkali metals) have one valence electron and therefore tend to form compounds with one atom of another element, such as hydrogen or oxygen, as seen in formulas like \(\mathrm{EH}\) or \(\mathrm{E_2O}\).

In the exercise, understanding periodic table groups was essential to complete it correctly. Recognizing the group to which an element belongs allows prediction of its chemical formula when combined with hydrogen or oxygen based on established patterns. The table provided illustrates this concept by giving a set pattern for deducing the chemical formulas of compounds for various elements across different groups.