Proton Examples in Chemistry

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

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

Concept Recap

A positively charged subatomic particle found in the nucleus of every atom, whose count defines the element's identity.

The identity badge of an atom—how many protons determines what element it is.

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: The number of protons is the atomic number and uniquely determines the element's identity.

Common stuck point: Protons don't change in chemical reactions—only electrons do.

Worked Examples

Example 1

easy
A sulfur atom has 16 protons. What is its atomic number, and how does the number of protons relate to its identity as sulfur?

Solution

  1. 1
    Recall that the atomic number Z is defined as the number of protons in the nucleus.
  2. 2
    Read the atomic number from the periodic table: Z = 16, so this atom has 16 protons.
  3. 3
    Every atom with exactly 16 protons is sulfur (S), regardless of how many neutrons or electrons it has.

Answer

Z = 16
Protons define the identity of an element. The atomic number Z is simply the proton count and is the most fundamental property of an element.

Example 2

medium
The mass of a single proton is approximately 1.673 \times 10^{-24} g. How many protons would it take to have a combined mass of 1 g?

Practice Problems

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

Example 1

easy
How many protons are in an atom of potassium (K, atomic number 19)?

Example 2

medium
Why doesn't sodium turn into magnesium during an ordinary chemical reaction, even if electrons are lost or gained?
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Related Concepts

AtomAtomic NumberNeutron

Background Knowledge

These ideas may be useful before you work through the harder examples.

atom