Which of the following best describes an atom?

• A. Two or more spheres joined together representing bonded atoms
• B. A cluster of spheres of different sizes and colors
• C. A single sphere representing a nucleus surrounded by electrons
• D. A lattice of repeating units forming a solid structure

Answer: (C)

Verified step by step guidance

1. Understand that an atom is the smallest unit of an element that retains the chemical properties of that element.
2. Recall that an atom consists of a nucleus, which contains protons and neutrons, surrounded by electrons in defined regions called orbitals.
3. Recognize that in simplified models, an atom is often represented as a single sphere symbolizing the nucleus with electrons around it, rather than multiple spheres joined together or clusters.
4. Differentiate this from molecules (two or more atoms bonded together) and solids (lattices of repeating units), which are larger structures made of many atoms.
5. Conclude that the best description of an atom is a single sphere representing a nucleus surrounded by electrons.