Classify the matter in the diagrams as elements, compounds, or mixtures in this IGCSE Chemistry worksheet.

Let's solve this Classification of Matter worksheet step by step. We are given 12 diagrams showing different arrangements of atoms (represented by black and white circles). Our goal is to classify each diagram as:

- A. Elements – made of only one type of atom (same atoms bonded together).
- B. Compounds – made of molecules with two or more *different* types of atoms chemically bonded.
- C. Mixtures of elements – two or more *different* elements (each in their elemental form) mixed together.
- D. Mixtures of compounds – two or more different compounds mixed together.
- E. Mixtures of elements and compounds – a combination of both elemental forms and compound molecules.

We will analyze each diagram:

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1)

All molecules have one black atom + two white atoms → same molecule throughout.
→ This is a compound (same chemical formula, different atoms).
✔ Answer: B

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2)

There are black atoms and white atoms, but they are not bonded — just randomly scattered.
→ Two different elements present in elemental form.
✔ Answer: C

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3)

Two types of molecules:
- One has two black atoms (a diatomic element),
- The other has one black + two white atoms (a compound).
→ So we have element + compound.
✔ Answer: E

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4)

All molecules are the same: one black + three white atoms → consistent compound.
→ All molecules are identical, made of different atoms.
✔ Answer: B

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5)

Only black atoms, all individual (no bonding shown).
→ But if they're separate atoms, they’re still an element (even if not bonded).
But in chemistry, atoms of the same element in atomic form (e.g., noble gases) count as elements.
So this is a pure element.
✔ Answer: A

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6)

All molecules are the same: four black atoms per molecule → likely a molecular element (like P₄).
→ Same atoms only → Element.
✔ Answer: A

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7)

All molecules are two white atoms bonded together → diatomic molecule.
→ Only one type of atom → Element.
✔ Answer: A

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8)

We see:
- Some single black atoms,
- Some single white atoms,
- And some molecules of one black + one white (a compound).
→ So we have elements (individual atoms) and a compound.
✔ Answer: E

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9)

We have:
- Single black atoms (element),
- Diatomic white molecules (element),
- And some molecules of one black + one white (compound).
→ So mixture of elements and compounds.
✔ Answer: E

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10)

Two types of molecules:
- One black + two white atoms → compound,
- Two white atoms bonded → element (diatomic).
→ So element + compound.
✔ Answer: E

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11)

All molecules are identical: one black + four white atoms → compound.
→ Pure substance, same molecule → Compound.
✔ Answer: B

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12)

All molecules are the same: one black + one white → compound.
→ Pure compound.
✔ Answer: B

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✔ Final Answers:

1) B
2) C
3) E
4) B
5) A
6) A
7) A
8) E
9) E
10) E
11) B
12) B

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🔍 Summary Key:

- A (Elements): Only one type of atom, possibly bonded (like O₂, P₄).
- B (Compounds): Molecules made of different atoms (e.g., H₂O, CO₂).
- C (Mixtures of elements): Different elements, but not chemically bonded (e.g., O₂ + N₂).
- D (Mixtures of compounds): Multiple different compounds.
- E (Mixtures of elements and compounds): Both elements and compounds coexist.

This worksheet tests understanding of pure substances vs. mixtures, and elements vs. compounds at a molecular level.

Let me know if you'd like a visual explanation for any!