Question

The most common charge associated with scandium in its compounds is \(3+.\) Indicate the chemical formulas you would expect for compounds formed between scandium and (a) iodine, ( b) sulfur, (c) nitrogen.

Short answer

The chemical formulas for the compounds formed between scandium and the given elements are: - Scandium and iodine: \(ScI_3\) - Scandium and sulfur: \(Sc_2S_3\) - Scandium and nitrogen: \(ScN\)

Step-by-step solution

Identify the charges of the anions (negative ions)

For this step, we need to determine the charges for the anions when iodine (I), sulfur (S), and nitrogen (N) form ions. From the periodic table: - Iodine (I) is in Group 17 (halogens), and forms a 1- ion (I⁻). - Sulfur (S) is in Group 16 (chalcogens), and forms a 2- ion (S²⁻). - Nitrogen (N) is in Group 15 (pnictogens), and forms a 3- ion (N³⁻).

Balance the charges to find the chemical formula for each compound

Now that we know the charge for each anion, we need to balance the charges between scandium (Sc³⁺) and the anions in each of the compounds. We can do this by determining the ratio between the cations and anions that results in a neutral charge. (a) Scandium and iodine: Sc³⁺ and I⁻. To balance the charges, we need 3 iodide ions for each scandium ion. Therefore, the chemical formula is \(ScI_3\). (b) Scandium and sulfur: Sc³⁺ and S²⁻. To balance the charges, we need 3 sulfur ions and 2 scandium ions. Therefore, the chemical formula is \(Sc_2S_3\). (c) Scandium and nitrogen: Sc³⁺ and N³⁻. The charges are already balanced as 3+ and 3- provide a neutral compound. Therefore, the chemical formula is \(ScN\). In conclusion, the chemical formulas for the compounds formed between scandium and the given elements are: - Scandium and iodine: \(ScI_3\) - Scandium and sulfur: \(Sc_2S_3\) - Scandium and nitrogen: \(ScN\)

Key concepts

Scandium Compounds

When discussing scandium compounds, we must first acknowledge that scandium (Sc) is a transition metal known for typically forming a +3 charge in its compounds. This trivalent state, denoted as Sc³⁺, means that scandium can combine with various anions (negatively charged ions) to form ionic compounds—both simple and complex.

For instance, when scandium reacts with halogens like iodine (I), which typically forms a -1 ion (I⁻), the positive and negative charges must balance to create a neutral compound. In the case of scandium and iodine, this is accomplished by having three iodine atoms bond with one scandium atom, resulting in the chemical formula of scandium iodide, or ScI₃. Understanding the charge of scandium is crucial in predicting the composition of its compounds with other elements.

Similar principles apply when scandium forms compounds with other nonmetals such as sulfur and nitrogen, with the resultant compounds exhibiting diverse properties suitable for a range of applications, from electronic materials to catalysts.

Balancing Chemical Charges

Balancing chemical charges is a fundamental skill in chemistry that ensures the total charge of an ionic compound is neutral. It's based on the principle that the total amount of positive charge must equal the total amount of negative charge in a stable, neutral compound.

To balance the charges, as seen in the example with scandium compounds, you need to make sure that the sum of charges from the cation (positively charged ion) and anion equals zero. If necessary, you'll use subscripts to show the number of ions needed to balance the charges. In some cases, as with scandium and iodine, a simple 1:3 ratio of cation to anion is needed, resulting in ScI₃.

However, situations become more complex with other anions like sulfur (S²⁻). Since the ratio must balance out the charges, a 2:3 ratio of scandium to sulfur ions is required, producing Sc₂S₃. This concept is integral to understanding how to write chemical formulas for ionic compounds correctly.

Ionic Compounds

Ionic compounds are formed when metals and nonmetals chemically bond through the transfer of electrons. Metals, which usually have a propensity to lose electrons, form positively charged ions or cations. On the opposite side, nonmetals, with a tendency to gain electrons, become negatively charged ions or anions.

The formation of such compounds is driven by the desire of atoms to obtain a full valence shell, often achieving a noble gas electron configuration. Ionic compounds are typically formed between elements with significantly different electronegativities—the measure of an atom's ability to attract electrons in a bond. This difference leads to the complete transfer of electrons, as highlighted in the creation of scandium nitride (ScN), where equal but opposite charges (+3 and -3) come together to form a compound with no overall charge.

Understanding how to determine the chemical formula of ionic compounds, like those formed from scandium, is essential for several scientific domains, including materials science, electrochemistry, and molecular physics, illustrating the versatility and significance of these chemical entities in both industry and research.