Atoms and Molar Mass: Exploring the Most Atoms in a Sample

Atoms are the basic units of matter that make up all elements. They consist of a nucleus containing protons and neutrons, with electrons orbiting around the nucleus. The number of atoms in a sample can vary based on the element and its molar mass.

In the given samples, the one that contains the most atoms is the 21.62 g sample of boron (B). This is because it has approximately 2 moles, while the other samples only have 1 mole each.

Understanding Molar Mass and Atom Count:

Each element has a specific molar mass, which can be found on the periodic table. The molar mass represents the mass of one mole of that element in grams. Here are the molar masses of the elements in the samples:

Magnesium (Mg): molar mass is about 24.305 g/mol
Potassium (K): molar mass is about 39.098 g/mol
Boron (B): molar mass is approximately 10.81 g/mol
Beryllium (Be): molar mass is about 9.0122 g/mol

To determine the number of moles in each sample, we divide the mass of the sample by its respective molar mass:

For Mg: Number of moles = 24.305 g / 24.305 g/mol = 1 mole
For K: Number of moles = 39.098 g / 39.098 g/mol = 1 mole
For B: Number of moles = 21.62 g / 10.81 g/mol ≈ 2 moles
For Be: Number of moles = 9.0122 g / 9.0122 g/mol = 1 mole

Therefore, the sample with 21.62 g of boron (B) contains the most atoms due to having a higher number of moles compared to the other samples. Understanding molar mass and mole calculation is key in determining the number of atoms in a sample.