Free Printable Atomic Structure Worksheets - Free Printable

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

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1. Label the parts of the atom shown below.

The diagram shows a simplified atomic model with:

- A central nucleus (with protons and neutrons)
- Electrons orbiting in shells (orbits)

Labels:
- The small black dots moving around the center → Electrons
- The central cluster (with both white and black circles) → Nucleus
- Inside the nucleus:
- White circles → Neutrons (no charge)
- Black circles → Protons (positive charge)

So, label the three lines as follows:

1. Electron (pointing to one of the outer black dots)
2. Nucleus (pointing to the central cluster)
3. Proton or Neutron — depending on which arrow points to which particle inside the nucleus.

But since there are two arrows pointing into the nucleus, likely:

- One arrow points to a proton (black circle)
- One arrow points to a neutron (white circle)

So final labels:

- Electron
- Nucleus
- Proton (for the black dot in the nucleus)
- Neutron (for the white dot in the nucleus)

> ⚠️ Note: There are three blank lines, but four parts. Likely the two inner arrows are for proton and neutron, and the outer one is electron.

✔ So, from top to bottom:
- Electron
- Proton
- Neutron

(Or vice versa — depends on the diagram’s labeling.)

But assuming:
- Top arrow → electron
- Right arrow → proton
- Bottom arrow → neutron

Then:
- Top: Electron
- Right: Proton
- Bottom: Neutron

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2. Answer the following questions.

#### a) What part of the atom has no charge?
➡️ Neutron

#### b) What part of the atom has a positive charge?
➡️ Proton

#### c) What part of the atom has a negative charge?
➡️ Electron

#### d) How many electrons can be held in the first orbital?
➡️ 2 electrons
*(First energy level/shell holds up to 2 electrons)*

#### e) How many electrons can be held in the second orbital?
➡️ 8 electrons
*(Second shell holds up to 8 electrons)*

#### f) The atomic number represents the number of which particles?
➡️ Protons

#### g) The mass number is determined by the sum of the numbers of which particles?
➡️ Protons and Neutrons

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3. Identify the atoms from their atomic structures.

We need to count:
- Number of protons (in nucleus)
- Number of electrons (in orbits)
- Use atomic number to identify the element

#### Atom 1:
- Nucleus: 6 black dots (protons), 6 white dots (neutrons) → 6 protons
- Electrons: 2 in first shell, 4 in second shell → total 6 electrons
- Atomic number = 6 → Element: Carbon (C)

✔ Carbon

#### Atom 2:
- Nucleus: 8 black dots (protons), 8 white dots (neutrons) → 8 protons
- Electrons: 2 in first shell, 6 in second shell → 8 electrons
- Atomic number = 8 → Element: Oxygen (O)

✔ Oxygen

#### Atom 3:
- Nucleus: 5 black dots (protons), 5 white dots (neutrons) → 5 protons
- Electrons: 2 in first shell, 3 in second shell → 5 electrons
- Atomic number = 5 → Element: Boron (B)

✔ Boron

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✔ Final Answers:

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1. Labels:

- Electron (outer dot)
- Proton (black dot in nucleus)
- Neutron (white dot in nucleus)

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2. Questions:

a) Neutron
b) Proton
c) Electron
d) 2
e) 8
f) Protons
g) Protons and Neutrons

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3. Identify atoms:

1. Carbon
2. Oxygen
3. Boron

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Let me know if you'd like this formatted as a printable answer key!