Atom Examples in Chemistry

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Atom.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.

Concept Recap

The smallest unit of an element that retains the chemical properties of that element.

The tiny building blocks everything is made of. Break matter down far enough, you get atoms.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Atoms have a nucleus (protons + neutrons) surrounded by electrons.

Common stuck point: Atoms are mostly empty space—the nucleus is tiny compared to the electron cloud.

Sense of Study hint: When analyzing an atom, start with the periodic table. First find the element's atomic number to determine the number of protons. Then for a neutral atom, electrons equal protons. Finally, use mass number minus atomic number to find neutrons.

Worked Examples

Example 1

easy
Describe the basic structure of an atom and identify the three subatomic particles along with their charges.

Solution

  1. 1
    An atom consists of a dense central nucleus surrounded by an electron cloud.
  2. 2
    The nucleus contains protons (charge +1) and neutrons (charge 0).
  3. 3
    Electrons (charge -1) orbit the nucleus in energy levels.

Answer

\text{Atom} = \text{nucleus (protons + neutrons)} + \text{electrons}
Understanding atomic structure is the foundation of all chemistry. Every atom is electrically neutral because the number of protons equals the number of electrons.

Example 2

medium
A carbon atom has 6 protons, 6 neutrons, and 6 electrons. Calculate the approximate mass of this atom in atomic mass units (amu), given that protons and neutrons each have a mass of approximately 1 amu and electrons have negligible mass.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy
If an atom has 8 protons, 8 neutrons, and 8 electrons, what element is it and what is its overall charge?

Example 2

easy
If you keep dividing a piece of copper into smaller and smaller pieces, what is the smallest unit that still retains copper's chemical properties?
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