The Density of Iridium: A Comprehensive Guide for Physics Students

Summary

Iridium is a rare and dense metal with a density of approximately 22.65 g/cm³, which is significantly higher than that of most common metals. The high density of iridium is due to its compact crystal structure, in which each iridium atom is closely packed with its neighbors. Iridium also has a number of other unique physical and chemical properties, such as high corrosion resistance, a very high melting point, and catalytic activity, making it valuable for a variety of applications.

Atomic Structure and Density of Iridium

iridium density

Iridium has an atomic number of 77 and an atomic mass of approximately 192.2 g/mol. It is a transition metal and part of the platinum group, which also includes platinum, palladium, rhodium, and ruthenium. Iridium has a face-centered cubic crystal structure, which is the same as that of other platinum group metals.

The density of a substance is defined as its mass per unit volume. In the case of iridium, the mass of a single iridium atom is approximately 192.2 g/mol, and the volume of a single iridium atom can be calculated using its atomic radius, which is approximately 135.7 pm (picometers). The volume of a sphere with a radius of 135.7 pm is given by the formula (4/3)πr³, which is approximately 9.03 x 10^-24 cm³. Therefore, the density of iridium is approximately 22.65 g/cm³, which is calculated by dividing the mass of a single iridium atom by the volume of a single iridium atom.

Physics Formula

The density (ρ) of a substance is given by the formula:

ρ = m/V

where m is the mass of the substance and V is its volume. In the case of iridium, m = 192.2 g/mol and V = 9.03 x 10^-24 cm³, so ρ = 192.2 g/mol / 9.03 x 10^-24 cm³ = 22.65 g/cm³.

Physics Examples

Consider a block of iridium with a volume of 1 cm³. The mass of this block would be approximately 22.65 g, since the density of iridium is 22.65 g/cm³. This means that a 1 cm³ block of iridium would have a mass of 22.65 g, regardless of its shape.

Physics Numerical Problems

Consider a sample of iridium with a mass of 50 g and a volume of 2.20 cm³. What is the density of this sample? To solve this problem, you would use the formula ρ = m/V, where m is the mass of the sample and V is its volume. In this case, m = 50 g and V = 2.20 cm³, so ρ = 50 g / 2.20 cm³ = 22.73 g/cm³. Therefore, the density of the sample is 22.73 g/cm³.

Experimental Determination of Iridium Density

The density of iridium can be determined experimentally by measuring the mass and volume of a sample of iridium. The mass of the sample can be measured using a balance, and the volume can be measured using a variety of methods, such as water displacement or geometric measurement. Once the mass and volume of the sample are known, the density can be calculated using the formula ρ = m/V.

Figures, Data Points, Values, and Measurements

The density of iridium can be measured experimentally using the following steps:

  1. Measure the mass of the iridium sample using a balance. Record the mass in grams (g).
  2. Measure the volume of the iridium sample using a method such as water displacement or geometric measurement. Record the volume in cubic centimeters (cm³).
  3. Calculate the density of the iridium sample using the formula ρ = m/V, where ρ is the density in g/cm³, m is the mass in g, and V is the volume in cm³.

Table 1 shows some example data points for the density of iridium:

Sample Mass (g) Volume (cm³) Density (g/cm³)
1 50.0 2.20 22.73
2 75.2 3.32 22.65
3 100.0 4.41 22.68

As shown in the table, the density of iridium is consistently around 22.65-22.73 g/cm³, which is in agreement with the theoretical value of 22.65 g/cm³ calculated earlier.

Theoretical Explanation of Iridium Density

The density of a substance is a fundamental physical property that is determined by its mass and volume. The density of a substance is an intensive property, which means that it does not depend on the size or shape of the sample. The density of a substance is also a scalar quantity, which means that it has magnitude but no direction.

In terms of physics, the density of a substance is related to its atomic structure and chemical composition. The density of a substance depends on the mass of its atoms and the volume of its crystal structure. The density of a substance can also be affected by factors such as temperature and pressure, which can cause changes in the volume of the substance.

Theorem

The density of a substance is a fundamental physical property that is determined by its mass and volume. The formula for density is:

ρ = m/V

where ρ is the density, m is the mass, and V is the volume.

The density of a substance is an intensive property, which means that it does not depend on the size or shape of the sample. The density of a substance is also a scalar quantity, which means that it has magnitude but no direction.

Conclusion

In conclusion, the density of iridium is a fundamental physical property that is determined by its mass and volume. The density of iridium is approximately 22.65 g/cm³, which is significantly higher than that of most common metals. The density of iridium is related to its atomic structure and chemical composition, and is an intensive property that is independent of the size or shape of the sample. The density of iridium can be measured experimentally using a balance and a variety of volume measurement techniques, and can be calculated using the formula ρ = m/V.

References:
– First-principles investigations of iridium low index surfaces, ResearchGate, https://www.researchgate.net/publication/243308680_First-principles_investigations_of_iridium_low_index_surfaces
– Stability of Iridium Single Atoms on Fe3O4(001) in the mbar … – NCBI, NCBI, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10544020/
– The stability number as a metric for electrocatalyst stability …, Canli, http://www.canli.dicp.ac.cn/literaturereading/20211016liulin.pdf