Question

Write a chemical formula for the compound containing one nitrogen atom for every three iodine atoms.

Short answer

The chemical formula for the compound is NI3.

Step-by-step solution

Understanding Compound Ratio

The first step is to understand the ratio given for the chemical formula. We need a compound with one nitrogen atom for every three iodine atoms, which implies a 1:3 ratio of nitrogen to iodine, respectively.

Writing the Chemical Symbols

Next, we write down the chemical symbols of the elements involved. Nitrogen is denoted by the symbol N, and Iodine is denoted by the symbol I.

Combining the Elements with Appropriate Subscripts

Since the ratio is 1:3 (Nitrogen:Iodine), we express this by using subscripts that reflect the number of atoms of each element. Thus, the chemical formula becomes NI3, using the subscript '3' to denote three iodine atoms.

Key concepts

Chemical Symbols

When we talk about chemical symbols, we refer to a concise way of representing elements in the chemical world. Each element is assigned a unique one or two-letter abbreviation that is standardized across the globe. The table of elements, commonly known as the periodic table, categorizes these symbols and lists elements by atomic number and characteristic properties.

For instance, in our exercise, the symbol 'N' stands for Nitrogen, and 'I' stands for Iodine. These symbols are the building blocks for writing chemical formulas and are crucial for communication in chemistry. Their universal acceptance makes it possible for scientists and students alike to understand and describe the composition of compounds regardless of their native language or locality.

Chemical symbols not only tell us what element is present but also, when combined with other notations such as numbers and dashes, can convey additional information about the compound. For instance, 'O2' represents two oxygen atoms bonded together, known as molecular oxygen.

Compound Ratio

The compound ratio is the proportion of atoms of each element present in a chemical compound. Ratios are fundamental for understanding the composition of compounds and for communicating that information succinctly. The ratio ensures that the chemical compound has the correct proportions of elements to match its defined structure and properties.

For example, as detailed in the exercise, if a compound consists of one nitrogen atom for every three iodine atoms, a 1:3 ratio is established. Ratios don't necessarily have to be in the simplest form; they just need to accurately reflect the quantity of each type of atom in a compound. This ratio guides the application of subscripts when writing a chemical formula. The numbers in a ratio may refer to moles of an element, equivalent to the number of atoms in 12 grams of carbon-12, providing a link between the microscopic atoms and a measurable quantity.

Subscripts in Chemistry

Subscripts play a significant role in chemistry equations and formulas. They appear as small numbers written immediately after and slightly below the symbol of an element. In a chemical formula, subscripts denote the number of atoms of the element that is present in a single molecule or formula unit of the compound. If there is no subscript written, it is understood that there is only one atom of that element present.

For instance, in the provided solution, the subscript '3' after the iodine symbol indicates there are three iodine atoms for every one nitrogen atom. This aligns with the ratio mentioned previously, translating the ratio into a quantitative formula. It's essential not to confuse subscripts with coefficients in chemical equations; while subscripts represent the number of atoms within a molecule, coefficients refer to the number of molecules present.

Manipulating these subscripts can change the identity of the compound, so it's important always to use them correctly in conjunction with the established compound ratio to create accurate chemical formulas.