Question

The electronic configurations of four elements \(L, P, Q\) and \(\mathrm{R}\) are given below. \(L=1 s^{2} 2 s^{2} 2 p^{4} ; Q=1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5}\) \(P=1 s^{2} 2 s^{2} 2 p^{6} 3 s^{1} ; R=1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2}\) The formula of ionic compounds that can be formed between these elements are (1) \(\mathrm{L}_{2} \mathrm{P}, \mathrm{RL}, \mathrm{PQ}, \mathrm{R}_{2} \mathrm{Q}\) (2) \(\mathrm{LP}, \mathrm{RL}, \mathrm{PQ}, \mathrm{RQ}\) (3) \(\mathrm{P}_{2} \mathrm{~L}, \mathrm{RL}, \mathrm{PQ}, \mathrm{RQ}_{2}\) (4) \(\mathrm{LP}, \mathrm{R}_{2} \mathrm{~L}, \mathrm{P}_{2} \mathrm{Q}, \mathrm{RQ}\)

Short answer

Option (3) contains the correct formulas: P2L, RL, PQ, RQ2.

Step-by-step solution

Identify the elements

Determine the element for each electronic configuration:- L: 1s^2 2s^2 2p^4 is Oxygen (O)- P: 1s^2 2s^2 2p^6 3s^1 is Sodium (Na)- Q: 1s^2 2s^2 2p^6 3s^2 3p^5 is Chlorine (Cl)- R: 1s^2 2s^2 2p^6 3s^2 is Magnesium (Mg)

Determine ionic charges

Identify the typical ionic charges for each element based on their group:- L (O): Typically forms a 2- ion (O^2-)- P (Na): Typically forms a 1+ ion (Na^+)- Q (Cl): Typically forms a 1- ion (Cl^-)- R (Mg): Typically forms a 2+ ion (Mg^2+)

Form possible combinations

Form ionic compounds by combining the cations and anions in ratios that balance the charges:- L (O^2-) with P (Na^+): Na2O- R (Mg^2+) with L (O^2-): MgO- P (Na^+) with Q (Cl^-): NaCl- R (Mg^2+) with Q (Cl^-): MgCl2

Match the compounds with the options

Compare the compounds formed with the given options:(1) L2P, RL, PQ, R2Q(2) LP, RL, PQ, RQ(3) P2L, RL, PQ, RQ2(4) LP, R2L, P2Q, RQ

Select the correct options

Identify the option with the correct combinations:- Na2O (L2P) matches P2L in option (3)- MgO (RL) matches RL in all options- NaCl (PQ) matches PQ in all options- MgCl2 (RQ2) matches RQ2 in option (3)

Key concepts

ionic compounds

Ionic compounds are formed when atoms of different elements transfer electrons between each other. This results in the formation of ions, which are atoms with an electrical charge. The positively charged ions, called cations, and the negatively charged ions, called anions, attract each other and bond to form ionic compounds.

For example, in the given question, oxygen (O) with electronic configuration 1s^2 2s^2 2p^4, tends to gain two electrons to complete its outer shell, becoming O^2-. On the other hand, sodium (Na) which has an electronic configuration 1s^2 2s^2 2p^6 3s^1, tends to lose one electron, forming Na^+. When these ions come together, they form the ionic compound Na2O.

In forming ionic compounds, the goal is to achieve charge neutrality. For instance, in MgO, magnesium (Mg^2+) and oxygen (O^2-) ions combine in a 1:1 ratio to balance the charges.

element identification

Identifying an element involves understanding its electronic configuration, which describes the distribution of electrons in an atom's shells and subshells. The electronic configuration helps determine the characteristics and behavior of the element, including its chemical reactivity and the type of bonds it can form.

For instance, element L with the configuration 1s^2 2s^2 2p^4 is identified as Oxygen (O). Similarly, element P with the configuration 1s^2 2s^2 2p^6 3s^1 is Sodium (Na). Understanding these configurations is crucial for predicting how these elements will interact with others to form compounds.

ionic charges

Ionic charges play a vital role in the formation of ionic compounds. The charge of an ion is determined by the loss or gain of electrons so that the atom achieves a stable electron configuration, often similar to the nearest noble gas.

For example, oxygen (O) typically forms a 2- ion (O^2-) because it needs two additional electrons to fill its outer shell. Sodium (Na) typically forms a 1+ ion (Na^+) because it loses one electron from its outer shell, making its electron configuration like that of neon (a noble gas).

Knowing the common charges of different ions helps predict the formulas of the compounds they will form, ensuring that the total positive and negative charges balance out. For instance, to form a neutral compound: Na^+ and Cl^- combine to form NaCl, while Mg^2+ and Cl^- combine to form MgCl2, requiring two Cl^- ions to balance one Mg^2+ ion.

chemical bonding

Chemical bonding is the process of atoms joining together to form new substances. The primary types of chemical bonds are ionic, covalent, and metallic bonds. In the exercise, we focused on ionic bonding.

Ionic bonds occur when electrons are transferred from one atom to another, resulting in the formation of ions. For example, when sodium (Na) combines with chlorine (Cl), an electron from Na is transferred to Cl, resulting in Na^+ and Cl^- ions. These oppositely charged ions attract each other to form the ionic bond in NaCl.

This bonding is crucial as it determines the structure, properties, and behavior of the compound. Ionic compounds generally have high melting and boiling points, are usually solid at room temperature, and can conduct electricity when dissolved in water or molten due to the movement of ions.