Atomic Structure Physical Science exercise - Free Printable

Let's go through each part of the worksheet step by step and solve it thoroughly.

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1. Label the parts of an atom in the diagram below

The diagram shows a simplified atomic model with:

- A central cluster (nucleus)
- Small dots orbiting around it (electrons)

Labeling:
- The central cluster is the nucleus.
- The small dots orbiting are electrons.
- The lines or circles they travel on are electron shells/orbitals.

Now, answer the questions:

a) What type of charge does a proton have?
→ Positive (+)

b) What type of charge does a neutron have?
→ Neutral (no charge / 0)

c) What type of charge does an electron have?
→ Negative (–)

d) Which two subatomic particles are located in the nucleus of an atom?
→ Protons and neutrons

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2. Fill in the numbers of protons (P), neutrons (N), and electrons (E)

We use:
- Atomic number = number of protons
- Number of electrons = number of protons (in neutral atoms)
- Neutrons = Mass number – Atomic number

#### Carbon (C):
- Atomic number = 6 → #P = 6
- Mass number ≈ 12.011 → rounded to 12
- #N = 12 – 6 = 6
- #E = 6 (neutral atom)

✔ #P = 6, #N = 6, #E = 6

#### Neon (Ne):
- Atomic number = 10 → #P = 10
- Mass number ≈ 20.108 → rounded to 20
- #N = 20 – 10 = 10
- #E = 10

✔ #P = 10, #N = 10, #E = 10

#### Potassium (K):
- Atomic number = 19 → #P = 19
- Mass number ≈ 39.098 → rounded to 39
- #N = 39 – 19 = 20
- #E = 19

✔ #P = 19, #N = 20, #E = 19

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3. Complete the table using your knowledge of the periodic table

We'll use:
- Atomic number = number of protons
- Number of electrons = number of protons (for neutral atoms)
- Mass number = protons + neutrons
- Neutrons = mass number – protons

Let’s fill row by row:

| Symbol | Atomic Number | Mass Number | Protons | Electrons | Neutrons |
|--------|---------------|-------------|---------|-----------|----------|
| Na | | | 11 | | 12 |

→ Na (Sodium): Atomic number = 11, so electrons = 11
Mass number = protons + neutrons = 11 + 12 = 23

✔ Atomic Number = 11, Mass Number = 23, Electrons = 11

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| K | | 39 | | 19 | |

→ K (Potassium): Atomic number = 19, so protons = 19, electrons = 19
Mass number = 39 → neutrons = 39 – 19 = 20

✔ Atomic Number = 19, Protons = 19, Neutrons = 20

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| | | | 38 | | 50 |

→ Protons = 38 → element is Strontium (Sr)
Atomic number = 38
Electrons = 38 (neutral)
Mass number = protons + neutrons = 38 + 50 = 88

✔ Symbol = Sr, Atomic Number = 38, Mass Number = 88, Electrons = 38

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| F | | | | 9 | 10 |

→ F (Fluorine): electrons = 9 → protons = 9 → atomic number = 9
Neutrons = 10 → mass number = 9 + 10 = 19

✔ Symbol = F, Atomic Number = 9, Mass Number = 19, Protons = 9

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| | 20 | 40 | | 20 | |

→ Atomic number = 20 → element is Calcium (Ca)
Protons = 20, electrons = 20
Neutrons = 40 – 20 = 20

✔ Symbol = Ca, Protons = 20, Neutrons = 20

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| | 50 | | | 50 | 69 |

→ Atomic number = 50 → element is Tin (Sn)
Protons = 50, electrons = 50
Neutrons = 69 → mass number = 50 + 69 = 119

✔ Symbol = Sn, Mass Number = 119

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| I | 53 | 127 | | | |

→ Iodine (I): atomic number = 53 → protons = 53, electrons = 53
Neutrons = 127 – 53 = 74

✔ Protons = 53, Electrons = 53, Neutrons = 74

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✔ Final Completed Table:

| Symbol | Atomic Number | Mass Number | Protons | Electrons | Neutrons |
|--------|---------------|-------------|---------|-----------|----------|
| Na | 11 | 23 | 11 | 11 | 12 |
| K | 19 | 39 | 19 | 19 | 20 |
| Sr | 38 | 88 | 38 | 38 | 50 |
| F | 9 | 19 | 9 | 9 | 10 |
| Ca | 20 | 40 | 20 | 20 | 20 |
| Sn | 50 | 119 | 50 | 50 | 69 |
| I | 53 | 127 | 53 | 53 | 74 |

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✔ Summary of Answers:

#### Question 1:
- Labels: Nucleus, electrons, electron shells
- a) Positive
- b) Neutral
- c) Negative
- d) Protons and neutrons

#### Question 2:
- Carbon: P=6, N=6, E=6
- Neon: P=10, N=10, E=10
- Potassium: P=19, N=20, E=19

#### Question 3: See completed table above.

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