Understanding the Concept of a Mole

In chemistry, a mole is a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles. It's similar to how we use "dozen" to represent 12 items. However, a mole represents a much larger number of particles.

Avogadro's Number and the Mole

The number of constituent particles (like atoms, molecules, ions, etc.) in one mole of a substance is defined by Avogadro's number. This number is named after Amedeo Avogadro, an Italian scientist.

Avogadro's number is approximately $6.02214076 \times 10^{23}$. For most calculations in school-level chemistry, this is rounded to $6.02 \times 10^{23}$.

So, by definition:

• One mole of atoms contains $6.02 \times 10^{23}$ atoms.
• One mole of molecules contains $6.02 \times 10^{23}$ molecules.
• One mole of ions contains $6.02 \times 10^{23}$ ions.
• One mole of electrons contains $6.02 \times 10^{23}$ electrons.

The specific element (like Carbon-12) determines the mass of one mole (molar mass), but the number of particles in one mole remains constant for any substance and is equal to Avogadro's number.

Calculating Atoms in One Mole of Carbon

The question asks for the number of atoms in one mole of Carbon (C – 12). According to the definition of a mole and Avogadro's number, one mole of any type of atom contains $6.02 \times 10^{23}$ atoms.

Therefore, one mole of Carbon (C – 12) atoms will contain $6.02 \times 10^{23}$ atoms.

Analyzing the Options

Let's look at the given options:

• Option 1: $6.02 \times 10^{26}$ - This is 1000 times larger than Avogadro's number.
• Option 2: $60.20 \times 10^{26}$ - This can be written as $6.02 \times 10^{27}$, which is significantly larger than Avogadro's number.
• Option 3: $8.06 \times 10^{20}$ - This number is much smaller than Avogadro's number.
• Option 4: $6.02 \times 10^{23}$ - This is the value of Avogadro's number, which represents the number of particles in one mole.

Based on the definition of a mole, Option 4 correctly represents the number of atoms in one mole of Carbon.

Revision Table: Mole Concept Basics

Additional Information on Moles and Atoms

The concept of the mole is fundamental in chemistry as it links the microscopic world of atoms and molecules to the macroscopic world of measurable quantities like mass and volume.

• The reason Carbon-12 is often used in the definition is that the mole was historically defined based on the number of atoms in exactly 12 grams of Carbon-12.
• While the number of atoms in one mole of Carbon is $6.02 \times 10^{23}$, the mass of one mole of Carbon is 12 grams. The mass per mole (molar mass) is different for different elements or compounds, but the number of particles per mole (Avogadro's number) is the same.
• Understanding the mole allows chemists to predict the amounts of reactants and products in chemical reactions.