Educational worksheet for students to practice identifying and counting atoms in chemical formulas.

Let's solve the problem step by step. The task is to count the number of atoms of each element in the given chemical formulas and fill in the table accordingly.

We’ll go through each compound one by one, identify the elements present, and count how many atoms of each element are in one molecule of the compound.

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1. NaOH

- Elements: Sodium (Na), Oxygen (O), Hydrogen (H)
- Each element appears once:
- Na: 1
- O: 1
- H: 1

✔ Answer:
- Na: 1
- O: 1
- H: 1

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2. HCl

- Elements: Hydrogen (H), Chlorine (Cl)
- Both appear once:
- H: 1
- Cl: 1

✔ Answer:
- H: 1
- Cl: 1

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3. ZnCl₂

- Elements: Zinc (Zn), Chlorine (Cl)
- Zn: 1 atom
- Cl: 2 atoms (subscript 2)

✔ Answer:
- Zn: 1
- Cl: 2

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4. Fe₂O₃

- Elements: Iron (Fe), Oxygen (O)
- Fe: 2 atoms (subscript 2)
- O: 3 atoms (subscript 3)

✔ Answer:
- Fe: 2
- O: 3

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5. C₆H₁₂O₆

- Elements: Carbon (C), Hydrogen (H), Oxygen (O)
- C: 6 atoms
- H: 12 atoms
- O: 6 atoms

✔ Answer:
- C: 6
- H: 12
- O: 6

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6. (NH₄)₃PO₄

This one is a bit more complex because it contains polyatomic ions in parentheses with subscripts.

Break it down:
- (NH₄)₃ means there are 3 NH₄⁺ groups
- PO₄ means one PO₄³⁻ group

Now count each element:

#### From (NH₄)₃:
- N: 3 × 1 = 3
- H: 3 × 4 = 12

#### From PO₄:
- P: 1
- O: 4

✔ Answer:
- N: 3
- H: 12
- P: 1
- O: 4

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Final Table:

| Chemical Formula | Elements | Number of Atoms |
|------------------|------------------|------------------|
| 1. NaOH | Na, O, H | Na: 1, O: 1, H: 1 |
| 2. HCl | H, Cl | H: 1, Cl: 1 |
| 3. ZnCl₂ | Zn, Cl | Zn: 1, Cl: 2 |
| 4. Fe₂O₃ | Fe, O | Fe: 2, O: 3 |
| 5. C₆H₁₂O₆ | C, H, O | C: 6, H: 12, O: 6 |
| 6. (NH₄)₃PO₄ | N, H, P, O | N: 3, H: 12, P: 1, O: 4 |

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✔ Summary:

You must list each element and its number of atoms per formula. Remember:
- Subscripts apply only to the element immediately before them.
- If a group is in parentheses with a subscript (like (NH₄)₃), multiply the atoms inside by the subscript.

Let me know if you'd like this formatted as a completed worksheet!