Free Printable Atomic Structure Worksheets - Free Printable

Absolutely! Let’s solve each part of the “Basic Atomic Structure” worksheet step by step with clear explanations.

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

*(Note: Since I can’t see the actual image, I’ll describe the standard atomic diagram and answer based on typical labeling.)*

In a standard Bohr model diagram:
- The center cluster is the nucleus, containing protons and neutrons.
- The orbiting circles/particles around the nucleus are electrons.

So, if there are blank lines pointing to:
- The central cluster → Nucleus
- The small particles inside the nucleus → Protons and Neutrons
- The particles orbiting outside → Electrons

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a) What type of charge does a proton have?

✔ Positive (+)
*Explanation:* Protons are positively charged subatomic particles found in the nucleus.

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b) What type of charge does a neutron have?

✔ Neutral (0 or no charge)
*Explanation:* Neutrons have no electrical charge — they are neutral.

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c) What type of charge does an electron have?

✔ Negative (–)
*Explanation:* Electrons are negatively charged particles that orbit the nucleus.

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d) Which two subatomic particles are located in the nucleus of an atom?

✔ Protons and Neutrons
*Explanation:* The nucleus contains protons and neutrons; electrons orbit outside the nucleus.

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## 2. Fill in #P (protons), #N (neutrons), #E (electrons) for given elements

We use this key:

> - Atomic Number = # of Protons = # of Electrons (in a neutral atom)
> - Mass Number ≈ Atomic Mass (rounded to nearest whole number)
> - # of Neutrons = Mass Number – Atomic Number

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Carbon (C)

- Atomic Number = 6 → So, #P = 6, #E = 6
- Atomic Mass = 12.011 → Round to 12 → #N = 12 – 6 = 6

✔ #P = 6, #N = 6, #E = 6

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Neon (Ne)

- Atomic Number = 10 → #P = 10, #E = 10
- Atomic Mass = 20.108 → Round to 20 → #N = 20 – 10 = 10

✔ #P = 10, #N = 10, #E = 10

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Potassium (K)

- Atomic Number = 19 → #P = 19, #E = 19
- Atomic Mass = 39.098 → Round to 39 → #N = 39 – 19 = 20

✔ #P = 19, #N = 20, #E = 19

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

We’ll fill in missing values using:
- Atomic Number = # Protons = # Electrons (neutral atom)
- Mass Number = # Protons + # Neutrons
- Use periodic table to find symbol from atomic number or vice versa.

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Row 1: Na

- Symbol: Na → Sodium → Atomic Number = 11
- Given: # Protons = 11 → so Atomic Number = 11
- # Electrons = 11 (same as protons)
- # Neutrons = 12 → Mass Number = 11 + 12 = 23

✔ Symbol: Na | Atomic Number: 11 | Mass Number: 23 | Protons: 11 | Electrons: 11 | Neutrons: 12

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Row 2: K

- Symbol: K → Potassium → Atomic Number = 19
- Mass Number = 39
- # Protons = 19
- # Electrons = 19
- # Neutrons = 39 – 19 = 20

✔ Symbol: K | Atomic Number: 19 | Mass Number: 39 | Protons: 19 | Electrons: 19 | Neutrons: 20

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Row 3: ? (Protons = 38, Neutrons = 50)

- # Protons = 38 → Atomic Number = 38 → Element is Strontium (Sr)
- # Electrons = 38
- Mass Number = 38 + 50 = 88

✔ Symbol: Sr | Atomic Number: 38 | Mass Number: 88 | Protons: 38 | Electrons: 38 | Neutrons: 50

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Row 4: F

- Symbol: F → Fluorine → Atomic Number = 9
- # Electrons = 9 → matches
- # Neutrons = 10 → Mass Number = 9 + 10 = 19

✔ Symbol: F | Atomic Number: 9 | Mass Number: 19 | Protons: 9 | Electrons: 9 | Neutrons: 10

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Row 5: Atomic Number = 20, Mass Number = 40

- Atomic Number 20 → Element is Calcium (Ca)
- # Protons = 20
- # Electrons = 20
- # Neutrons = 40 – 20 = 20

✔ Symbol: Ca | Atomic Number: 20 | Mass Number: 40 | Protons: 20 | Electrons: 20 | Neutrons: 20

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Row 6: Atomic Number = 50, # Electrons = 50, # Neutrons = 69

- Atomic Number 50 → Element is Tin (Sn)
- Mass Number = 50 + 69 = 119

✔ Symbol: Sn | Atomic Number: 50 | Mass Number: 119 | Protons: 50 | Electrons: 50 | Neutrons: 69

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Row 7: I (Iodine), Atomic Number = 53, Mass Number = 127

- # Protons = 53
- # Electrons = 53
- # Neutrons = 127 – 53 = 74

✔ Symbol: I | Atomic Number: 53 | Mass Number: 127 | Protons: 53 | Electrons: 53 | Neutrons: 74

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## ✔ Final Completed Table:

| Symbol | Atomic Number | Mass Number | Number of Protons | Number of Electrons | Number of 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 Key Concepts:

- Proton: + charge, in nucleus
- Neutron: no charge, in nucleus
- Electron: – charge, orbits nucleus
- Atomic Number = Protons = Electrons (in neutral atoms)
- Mass Number ≈ Protons + Neutrons

You’ve now mastered basic atomic structure! Great job! 💪🔬

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