Indium consists of two isotopes, ¹¹³₄₉In and ¹¹⁵₄₉In. If the atomic mass for indium on the periodic table is 114.8, are there more atoms of ¹¹³₄₉In or ¹¹⁵₄₉In in a sample of indium?

Verified step by step guidance

1. Identify the isotopes of indium: ¹¹³₄₉In and ¹¹⁵₄₉In.
2. Understand that the atomic mass of indium on the periodic table (114.8) is a weighted average of the masses of its isotopes.
3. Set up an equation to represent the weighted average: (mass of ¹¹³₄₉In) * (fraction of ¹¹³₄₉In) + (mass of ¹¹⁵₄₉In) * (fraction of ¹¹⁵₄₉In) = 114.8.
4. Let x be the fraction of ¹¹³₄₉In, then the fraction of ¹¹⁵₄₉In is (1 - x).
5. Solve the equation for x to determine which isotope is more abundant.

Key Concepts

Isotopes

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses. For indium, the isotopes ¹¹³₄₉In and ¹¹⁵₄₉In have atomic masses of 113 and 115, respectively. Understanding isotopes is crucial for analyzing the composition of elements and their relative abundances in a sample.

Atomic Mass

Atomic mass is the weighted average mass of an element's isotopes, measured in atomic mass units (amu). The atomic mass of indium is given as 114.8, which indicates that the average mass of indium atoms in a sample is influenced by the relative abundances of its isotopes. This concept is essential for determining the proportion of each isotope present in a sample.

Relative Abundance

Relative abundance refers to the proportion of each isotope of an element present in a natural sample. To find out whether there are more atoms of ¹¹³₄₉In or ¹¹⁵₄₉In in a sample of indium, one must consider the atomic mass and the isotopes' contributions to that mass. The isotope with a lower atomic mass will generally be more abundant if the average atomic mass is closer to that isotope's mass.