Atomic Structure Worksheet with interactive exercises on atomic diagrams, element identification, and atomic data.

Atomic Structure Worksheet Solution and Explanation

#### 1. Using the periodic table, write the name of the element next to each atom.

To identify the elements, we need to count the number of protons (which is equal to the atomic number) in each atom's nucleus.

- First Atom:
- Protons = 2
- Element: Helium (He)

- Second Atom:
- Protons = 8
- Element: Oxygen (O)

- Third Atom:
- Protons = 12
- Element: Magnesium (Mg)

Answers:
- First Atom: Helium
- Second Atom: Oxygen
- Third Atom: Magnesium

---

#### 2. Draw the following atoms.

To draw the atoms, we need to know their atomic numbers (number of protons) and electron configurations.

- Hydrogen (H):
- Atomic number = 1
- Electrons = 1
- Drawing: One proton in the nucleus and one electron in the first shell.

- Boron (B):
- Atomic number = 5
- Electrons = 5
- Drawing: Five protons in the nucleus, two electrons in the first shell, and three electrons in the second shell.

- Helium (He):
- Atomic number = 2
- Electrons = 2
- Drawing: Two protons in the nucleus and two electrons in the first shell.

Drawings:
- Hydrogen:
```
Nucleus: O
Electron: ●
```

- Boron:
```
Nucleus: OOOOO
First Shell: ●●
Second Shell: ●●●
```

- Helium:
```
Nucleus: OO
Electron: ●●
```

---

#### 3. Fill in the blanks.

The diagram shows an oxygen atom with its atomic number, symbol, and atomic mass. We need to fill in the blanks based on the information provided.

- Atomic Number: 8
- Symbol: O
- Element Name: Oxygen
- Atomic Mass: 15.999

Filled Blanks:
```
8 ← Atomic Number
O ← Symbol
Oxygen ← Element Name
15.999 ← Atomic Mass
```

---

#### What parts of an atom does the atomic number represent?

The atomic number represents:
1. Number of protons in the nucleus.
2. Number of electrons in a neutral atom (since the number of protons equals the number of electrons in a neutral atom).

Answer:
Protons and Electrons

---

#### How do you figure the number of neutrons?

The number of neutrons can be calculated using the following formula:
\[
\text{Number of Neutrons} = \text{Atomic Mass (rounded to the nearest whole number)} - \text{Atomic Number}
\]

---

#### Fill in the blanks for Carbon (C) and Potassium (K).

##### Carbon (C):
- Atomic Number = 6
- Atomic Mass = 12.003 (rounded to 12)
- Number of Protons = Atomic Number = 6
- Number of Electrons = Atomic Number = 6
- Number of Neutrons = Atomic Mass - Atomic Number = 12 - 6 = 6

##### Potassium (K):
- Atomic Number = 19
- Atomic Mass = 39.098 (rounded to 39)
- Number of Protons = Atomic Number = 19
- Number of Electrons = Atomic Number = 19
- Number of Neutrons = Atomic Mass - Atomic Number = 39 - 19 = 20

Filled Blanks:
- Carbon:
- # of protons = 6
- # of electrons = 6
- # of neutrons = 6
- Potassium:
- # of protons = 19
- # of electrons = 19
- # of neutrons = 20

---

Final Answers:

1. Elements:
- First Atom: Helium
- Second Atom: Oxygen
- Third Atom: Magnesium

2. Atom Drawings:
- Hydrogen: One proton, one electron.
- Boron: Five protons, two electrons in the first shell, three in the second shell.
- Helium: Two protons, two electrons in the first shell.

3. Blanks Filled:
- Atomic Number: 8
- Symbol: O
- Element Name: Oxygen
- Atomic Mass: 15.999

4. Parts Represented by Atomic Number:
- Protons and Electrons

5. Calculating Neutrons:
- Use the formula: Number of Neutrons = Atomic Mass (rounded) - Atomic Number.

6. Carbon (C):
- # of protons = 6
- # of electrons = 6
- # of neutrons = 6

7. Potassium (K):
- # of protons = 19
- # of electrons = 19
- # of neutrons = 20

Boxed Final Answer:
\[
\boxed{
\text{1. Helium, Oxygen, Magnesium; 2. Drawings as explained; 3. 8, O, Oxygen, 15.999; 4. Protons and Electrons; 5. Formula explained; 6. C: 6, 6, 6; K: 19, 19, 20}
}
\]