Question

What is the average atomic mass (in amu) of iron atoms? What would 299 iron atoms weigh? How many iron atoms are present in a sample of iron that has a mass of 5529.2 amu?

Short answer

The average atomic mass of iron atoms is 55.845 amu. The total weight of 299 iron atoms is approximately 16712.155 amu. In a sample of iron with a mass of 5529.2 amu, there are approximately 99 iron atoms.

Step-by-step solution

Find the average atomic mass of iron atoms

The average atomic mass of iron is given as 55.845 amu. This information can be found in the periodic table.

Calculate the weight of 299 iron atoms

To find the weight of 299 iron atoms, we just need to multiply the average atomic mass of a single iron atom by the number of atoms. So, Weight of 299 iron atoms = (Average atomic mass of iron) × (Number of iron atoms) Weight of 299 iron atoms = 55.845 amu × 299 Now, let's calculate the value: Weight of 299 iron atoms = 16712.155 amu

Calculate the number of iron atoms in a sample weighing 5529.2 amu

To find out how many iron atoms are present in the sample, we have to divide the mass of the sample by the average atomic mass of iron. So, Number of iron atoms = (Mass of the sample) / (Average atomic mass of iron) Number of iron atoms = 5529.2 amu / 55.845 amu Now, let's calculate the value: Number of iron atoms ≈ 99 So, there are approximately 99 iron atoms present in the given sample. In summary: - The average atomic mass of iron atoms is 55.845 amu. - 299 iron atoms weigh approximately 16712.155 amu. - There are approximately 99 iron atoms present in a sample of iron that has a mass of 5529.2 amu.

Key concepts

Average Atomic Mass

The concept of average atomic mass is fundamental in chemistry and is crucial for understanding elements at the atomic level.
The average atomic mass of an element is calculated based on the weighted average of the masses of its isotopes. These isotopes differ in the number of neutrons in their nuclei, leading to different atomic masses.
Most naturally occurring elements have more than one isotope.

• Each isotope contributes to the atomic mass according to its natural abundance. For example, if an element has two isotopes, one with a mass of 20 amu occurring 75% of the time, and another with a mass of 22 amu occurring 25% of the time, then the average atomic mass is calculated by multiplying each mass by its abundance and adding them together.
• In the case of iron, its average atomic mass is 55.845 amu, as listed on the periodic table. This value gives us a practical way to consider iron atoms when they are in a mixture of isotopes, as they naturally occur.
• The average atomic mass is expressed in atomic mass units (amu), a standard unit used to quantify mass at the atomic or molecular scale.

Understanding this concept allows you to perform calculations, such as determining the total mass of a given number of atoms or determining how many atoms are in a specific mass, as seen in the exercise.

Iron Atoms

Iron is one of the most abundant metals on Earth and is a key element in many biological and industrial processes. Iron atoms play a critical role in a variety of scientific disciplines.
In the exercise, the average atomic mass of iron is used to calculate the weight of a set number of iron atoms. This helps to grasp the scale at which atoms contribute to the mass of a material.

• An iron atom has a characteristic atomic weight of approximately 55.845 amu, reflecting the mixed presence of different iron isotopes.
• When you multiply the atomic mass (55.845 amu) by the number of atoms (299), this provides a straightforward way to determine their total weight, yielding 16712.155 amu in this instance.
• This method is also reversed to find the number of atoms in a known total mass, highlighting the importance of these calculations in experimental and theoretical chemistry.

By understanding how to perform these calculations, you can better appreciate the interaction of atoms like iron in various chemical contexts.

Periodic Table

The periodic table is one of the most important tools in chemistry, organizing all known elements in a comprehensible layout. It helps scientists and students alike to quickly find information about atomic masses, elemental properties, and relationships between elements.

• The periodic table lists elements by their atomic number, which is the number of protons found in the nucleus of an atom. This is also equal to the number of electrons in a neutral atom.
• The order of elements in the periodic table also relates to their electron configurations and recurring chemical properties, providing insight into their chemical behavior.
• A vital feature displayed on the periodic table is the average atomic mass, typically found beneath an element's symbol. For iron, this value is essential for calculations involving its atomic structure, as seen in the original exercise with its mass of 55.845 amu.

The periodic table serves as a quick reference for these core qualities and offers a structural approach to understanding chemical elements and their interactions.