Educational worksheet on atoms and molecules, featuring matching exercises for science students.

Let’s solve this step by step.

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Part 1: Match the words and definitions

We have four words to match:
- a molecule
- an atom
- a hundred
- water

And four sentences with blanks:

1. “This is the smallest particle of matter. It’s _________”
→ The smallest particle of matter is an atom. Atoms are the basic building blocks.

2. “This is formed by two or more different atoms. It’s _________”
→ When atoms join together, they form a molecule. (Note: even if same atoms, like O₂, it’s still a molecule — but here it says “different atoms”, so definitely a molecule.)

3. “H2O molecules make _________”
→ H2O is the chemical formula for water. So H2O molecules make water.

4. “There are approximately _________ different types of atoms.”
→ In nature, there are about a hundred naturally occurring elements (atoms). Actually, there are 94 naturally occurring elements, but scientists often say “about a hundred” in simple terms. So we use a hundred.

✔ So matches are:
- Smallest particle → an atom
- Formed by two or more different atoms → a molecule
- H2O makes → water
- Approximately ___ types of atoms → a hundred

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Part 2: Match each atom to the letter which represents it

Left column: Element names
Right column: Chemical symbols

We need to match them correctly.

Recall common element symbols:

- Iron → Fe (from Latin *Ferrum*)
- Gold → Au (from Latin *Aurum*)
- Silver → Ag (from Latin *Argentum*)
- Oxygen → O
- Hydrogen → H
- Carbon → C

Now let’s pair them:

Left side:
- Iron → Fe
- Gold → Au
- Silver → Ag
- Oxygen → O
- Hydrogen → H
- Carbon → C

Right side has: O, Ag, H, C, Au, Fe — exactly the symbols we need.

So matching:

Iron → Fe
Gold → Au
Silver → Ag
Oxygen → O
Hydrogen → H
Carbon → C

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Final Answer:

Part 1:
- This is the smallest particle of matter. It’s an atom
- This is formed by two or more different atoms. It’s a molecule
- H2O molecules make water
- There are approximately a hundred different types of atoms.

Part 2:
- Iron → Fe
- Gold → Au
- Silver → Ag
- Oxygen → O
- Hydrogen → H
- Carbon → C