Question

What is the mass number of an iron atom that has 28 neutrons?

Short answer

The mass number of the iron atom is 54.

Step-by-step solution

Understand Mass Number

The mass number of an atom is the sum of the number of protons and neutrons in its nucleus. It reflects the total number of these particles, which make up the atom's mass.

Determine the Number of Protons in Iron

Iron, represented by the symbol Fe, has an atomic number of 26. This means every iron atom has 26 protons.

Use the Mass Number Formula

The formula for mass number (A) is: \( A = Z + N \), where \( Z \) is the number of protons, and \( N \) is the number of neutrons. Here, \( Z = 26 \) and \( N = 28 \).

Calculate the Mass Number

Plug the known values into the formula: \( A = 26 + 28 = 54 \). Thus, the mass number of the iron atom is 54.

Key concepts

Protons

Protons are subatomic particles found within the nucleus of an atom. They carry a positive charge, which helps to balance the negative charge of electrons orbiting the nucleus.
The number of protons in an atom is a fundamental characteristic, defining what element the atom represents. For example, hydrogen has one proton, while iron, denoted by the symbol Fe, always has 26 protons.

• The presence of protons gives each element its unique identity on the periodic table.
• They contribute significantly to the mass of an atom but possess only one unit of positive charge.
• The number of protons in an atom is equal to its atomic number.

Understanding protons is essential, as they contribute to the atom's overall structure and the way it interacts with other atoms in chemical reactions.

Neutrons

Neutrons are neutral subatomic particles found in the nucleus alongside protons. They carry no electrical charge, which means they do not attract or repel charged particles. This neutrality allows neutrons to help stabilize the nucleus by offsetting the repulsive forces between positively charged protons.
The number of neutrons can vary in atoms of the same element, leading to different isotopes. For iron, which has an atomic number of 26, the number of neutrons present can differ, but in this context, we consider an iron atom with 28 neutrons.

• Neutrons contribute to the atomic mass, similar to protons.
• Without neutrons, the nucleus would be unstable due to repulsion between protons.
• They play a role in nuclear reactions and stability.

The presence and number of neutrons are crucial for understanding isotopes and the physical properties of elements.

Atomic Number

The atomic number is a key characteristic of an element, corresponding directly to the number of protons in the nucleus of its atom. Each element on the periodic table is unique due to its specific atomic number.
For example, iron has an atomic number of 26. This tells us that every iron atom contains exactly 26 protons, distinguishing it from other elements like carbon, which has six protons.

• The atomic number is denoted by the symbol \( Z \).
• It helps in identifying the element and its position on the periodic table.
• The atomic number influences chemical properties and bonding behavior.

Understanding atomic numbers is crucial for anyone studying chemistry, as it directly relates to an element's identity and behavior in reactions.

Iron

Iron is a chemical element with the symbol Fe, derived from its Latin name, Ferrum. It is a metal commonly known for its strength and magnetic properties, playing an essential role both biologically and industrially.
In the context of chemistry, iron has an atomic number of 26, which means it contains 26 protons in its nucleus. The stability and properties of iron can also vary with a different number of neutrons, leading to various isotopes.

• Iron's atomic mass is significantly contributed by its protons and neutrons.
• It is a transition metal and has common oxidation states of +2 and +3.
• Iron is widely used in construction, tools, and as a component in blood hemoglobin.

Iron's versatility and abundance make it critical in many sectors, including building, technology, and health.