Question

Refer to the periodic table and state the mass of \(6.02 \times 10^{23}\) atoms of each of the following nonmetals: (a) carbon (b) sulfur (c) selenium (d) iodine

Short answer

For \(6.02 \times 10^{23}\) atoms, the masses are: Carbon - 12.01 g, Sulfur - 32.06 g, Selenium - 78.96 g, and Iodine - 126.90 g.

Step-by-step solution

Understanding Avogadro's Number

Avogadro's number, \(6.02 \times 10^{23}\), represents the number of atoms, molecules, or particles in one mole of a substance. This means that the atomic mass of an element (in grams) is the mass of \(6.02 \times 10^{23}\) atoms of that element.

Identify Atomic Mass from the Periodic Table

Look up the atomic mass of each nonmetal. The atomic masses are approximately: - Carbon (C): 12.01 g/mol - Sulfur (S): 32.06 g/mol - Selenium (Se): 78.96 g/mol - Iodine (I): 126.90 g/mol

Calculate the Mass of One Mole of Atoms

Since \(6.02 \times 10^{23}\) atoms constitute one mole, the mass of this quantity of atoms corresponds directly to the atomic mass of the element. Therefore,- Mass of \(6.02 \times 10^{23}\) carbon atoms = 12.01 g- Mass of \(6.02 \times 10^{23}\) sulfur atoms = 32.06 g- Mass of \(6.02 \times 10^{23}\) selenium atoms = 78.96 g- Mass of \(6.02 \times 10^{23}\) iodine atoms = 126.90 g

Key concepts

Atomic Mass

The atomic mass of an element is the mass of a single atom, typically measured in atomic mass units (amu). However, in common chemical practice, we often use grams per mole (g/mol) since it is more convenient for calculations in the lab. The periodic table provides the atomic masses of elements, which are averages that account for the varied isotopes found naturally.

For example, carbon has several isotopes, but carbon-12 is the most common. Hence, the atomic mass of carbon is listed as 12.01 g/mol. This means that one mole of carbon atoms indeed weighs about 12.01 grams. Similarly, the atomic masses of sulfur, selenium, and iodine indicate the same principles. Their placements and values on the periodic table guide us in calculating the weight of one mole of each element's atoms.

Understanding atomic mass is essential for predicting the proportions of substances that will interact in chemical reactions.

Mole Concept

The mole concept is a fundamental aspect of chemistry which links the atomic scale to the macroscopic world we observe. A mole is simply a unit of measurement that quantifies the amount of substance. One mole of any element or compound contains Avogadro's number of entities, which is precisely defined as \(6.02 \times 10^{23}\) atoms, molecules, or formula units.

This is a very large number because atoms and molecules are extremely small. To visualize, just as one dozen equals 12 objects, one mole equals \(6.02 \times 10^{23}\) of any given entities. When we say that the atomic mass of carbon is 12.01 g/mol, it implies one mole of carbon atoms weighs 12.01 grams, which contains \(6.02 \times 10^{23}\) atoms.

The concept of the mole enables chemists to weigh out amounts of substances such that they contain equivalent numbers of molecules or atoms, simplifying the stoichiometry of reactions and making laboratory connections more feasible.

Periodic Table

The periodic table is not just a tabular display of chemical elements. It is a powerful resource that encapsulates information about every known element. Each element's box on the periodic table provides its atomic number, element symbol, and atomic mass.

The organization of the periodic table reveals patterns and relationships between the elements. Elements are arranged by increasing atomic number and, as a result, similar properties recur periodically—a phenomenon known as periodicity.

When tasked with determining the mass of a mole of atoms of nonmetals like carbon, sulfur, selenium, or iodine, the periodic table provides an immediate reference with the atomic masses. These values tell us how much one mole of their atoms will weigh.

• Atomic number: indicates the number of protons (and electrons in a neutral atom).
• Elemental symbol: a one or two-letter abbreviation derived from the element’s name.
• Atomic mass: average mass reflecting all natural isotopes.

Using the periodic table effectively can enhance one’s understanding of chemical properties and reactions.