Problem 97 - Chemistry The Central Science In Si Units

Question

Using a suitable reference such as the CRC Handbook of Chemistry and Physics or http://www.webelements.com, look up the following information for nickel: \((\mathbf{a})\) the number of known isotopes, \((\mathbf{b})\) the atomic masses (in \(\mathrm{u}),(\mathbf{c})\) the natural abundances of the five most abundant isotopes.

Step-by-Step Solution

Answer

Nickel has 31 known isotopes, with atomic masses approximately 57.935 u, 59.930 u, 60.931 u, 61.928 u, and 63.928 u. The natural abundances are 68.077%, 26.223%, 1.140%, 3.634%, and 0.926% respectively.

Step 1: Researching Known Isotopes

Look up the number of known isotopes for nickel by using a reliable online source like WebElements or the CRC Handbook of Chemistry and Physics. Nickel has 31 known isotopes.

Step 2: Finding Atomic Masses of Isotopes

Identify the atomic masses (in atomic mass units, u) for the isotopes of nickel. The standard atomic masses for the natural isotopes are approximately: - Nickel-58: 57.935 u - Nickel-60: 59.930 u - Nickel-61: 60.931 u - Nickel-62: 61.928 u - Nickel-64: 63.928 u.

Step 3: Determining Natural Abundances

Use the same reliable sources to find the natural abundances of the five most abundant isotopes of nickel: - Nickel-58: 68.077% - Nickel-60: 26.223% - Nickel-61: 1.140% - Nickel-62: 3.634% - Nickel-64: 0.926%.

Key Concepts

Atomic Mass Units

Atomic mass units (AMU), symbolized as "u," are a key concept when understanding the weight of atoms and isotopes. They are used to express atomic and molecular weights. One atomic mass unit is defined as one twelfth of the mass of a carbon-12 atom. This unit helps to accurately describe the mass of atomic-scale particles. For example, Nickel-58 has an atomic mass of approximately 57.935 u. Knowing these masses helps scientists compare and analyze elements in a meaningful way.

Natural Abundance

Natural abundance refers to the relative proportion of each isotope of an element in nature. It's expressed as a percentage of the total amount of the element found on Earth. For nickel, these proportions are very important. For instance, Nickel-58, one of the most common isotopes, makes up about 68.077% of naturally occurring nickel. This helps in calculations for average atomic weight and in practical applications of nickel. Understanding natural abundance gives insights into the element's stability and availability.

Nickel-58

Nickel-58 is the most abundant isotope of nickel, accounting for about 68.077% of the nickel found naturally. It is crucial in the nuclear science field due to its stability. With an atomic mass close to 57.935 u, it is often used in scientific calculations involving nickel's atomic weight. This stability and abundance make nickel-58 an important subject of study for anyone working with nickel-related reactions or compositions.

Nickel-60

Nickel-60 is the second most common isotope of nickel, with a natural abundance of about 26.223%. It has an atomic mass of approximately 59.930 u. Nickel-60 is important in various fields including chemistry and material science because of its specific properties. For example, it is involved in certain radioactive decay processes, making it significant for dating geological and astronomical materials. Despite being less abundant than Nickel-58, it plays a pivotal role in scientific research.

CRC Handbook of Chemistry and Physics

The CRC Handbook of Chemistry and Physics is a comprehensive reference book offering accurate scientific information. It is often used for finding details about chemical elements, including isotopic data like those for nickel. This handbook is crucial for scientists and students alike as it provides reliable values for atomic masses, natural abundances, and other properties. It's like having all essential data in one place, making it a go-to source for researchers exploring chemistry and physics.