Sum it up - Atoms worksheet - Free Printable

Let's solve each part of this worksheet step by step.

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Question 19: Label each part of the Periodic Table Symbol Box

We are given a box representing manganese (Mn) on the periodic table:

```
25
Mn
Manganese
54.94
```

The parts to label are:

- Top left: Atomic Number → 25
- Top right: Mass Number → This is not shown directly, but in this case, it's implied as the average atomic mass (54.94), so actually, the top right number is the Mass Number only if it’s a specific isotope. But here, since it's 54.94, that’s the atomic mass, not mass number. So we need to clarify.

Wait — let's look at the layout carefully:

```
[25] ← Top left
Mn
Manganese
54.94 ← Bottom
```

In standard periodic table boxes:

- Top left: Atomic Number (number of protons) → 25
- Symbol: Mn (element symbol)
- Name: Manganese (element name)
- Bottom: Average Atomic Mass → 54.94

So labeling:

- Arrow pointing to 25: Atomic Number
- Arrow pointing to Mn: Chemical Symbol
- Arrow pointing to Manganese: Element Name
- Arrow pointing to 54.94: Atomic Mass

✔ So fill in:

- Left arrow to 25: Atomic Number
- Right arrow to 25: Atomic Number? Wait — there are two arrows pointing to 25? Let's see the diagram again.

Actually, looking at your image:

- One arrow points to 25 from the left → label: Atomic Number
- One arrow points to 25 from the right → same thing? That doesn’t make sense.

But likely, the top left corner has the atomic number, and the bottom has the atomic mass.

Looking at the structure:

```
25
Mn
Manganese
54.94
```

So the labels should be:

- Top left (25): Atomic Number
- Center (Mn): Chemical Symbol
- Below Mn (Manganese): Element Name
- Bottom (54.94): Atomic Mass

So the blanks are:

- Left arrow → Atomic Number
- Right arrow → Atomic Number? No, probably the right arrow points to 25 too? That seems redundant.

Wait — perhaps the arrows are pointing to different parts.

Looking at the image:

- One arrow points to 25 from the left → label: Atomic Number
- One arrow points to 25 from the right → same? Or maybe it's meant to point to something else?

Wait — no. The 25 is in the top left. Then below it is Mn, then Manganese, then 54.94.

So likely:

- Arrow to 25: Atomic Number
- Arrow to Mn: Chemical Symbol
- Arrow to Manganese: Element Name
- Arrow to 54.94: Atomic Mass

And there are four arrows, so four labels.

Thus:

1. Arrow to 25 → Atomic Number
2. Arrow to Mn → Chemical Symbol
3. Arrow to Manganese → Element Name
4. Arrow to 54.94 → Atomic Mass

✔ So fill in:

- First blank (left of 25): Atomic Number
- Second blank (right of 25): ??? Wait — no, the arrows seem to go to different parts.

From the diagram:

- Top left arrow → 25 → Atomic Number
- Top right arrow → 25 → same? Probably not.

Wait — perhaps the top right is not labeled. Actually, the 25 is in the top left, and the symbol Mn is centered, and 54.94 is bottom.

So likely:

- Arrow pointing to 25: Atomic Number
- Arrow pointing to Mn: Chemical Symbol
- Arrow pointing to Manganese: Element Name
- Arrow pointing to 54.94: Atomic Mass

So the four blanks are:

- Left of 25 → Atomic Number
- Right of 25 → ???

Wait — perhaps the top right is mass number, but it's not shown. In this case, 25 is atomic number, 54.94 is average atomic mass.

So the correct labels are:

- 25: Atomic Number
- Mn: Chemical Symbol
- Manganese: Element Name
- 54.94: Atomic Mass

So the four blanks:

1. Arrow to 25 → Atomic Number
2. Arrow to Mn → Chemical Symbol
3. Arrow to Manganese → Element Name
4. Arrow to 54.94 → Atomic Mass

✔ Answer for 19:

- Left arrow to 25: Atomic Number
- Right arrow to 25: ??? — wait, maybe the arrows are misaligned.

Actually, based on standard diagrams, the 25 is atomic number, Mn is symbol, Manganese is name, 54.94 is atomic mass.

So the four labels:

- Atomic Number (points to 25)
- Chemical Symbol (points to Mn)
- Element Name (points to Manganese)
- Atomic Mass (points to 54.94)

So fill in accordingly.

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Question 20: Complete the table

| Element | Chemical Symbol | Atomic Number | Atomic Mass | Mass Number | Isotopic Notation | # of protons | # of electrons | # of neutrons |
|---------------|------------------|----------------|--------------|---------------|--------------------|---------------|----------------|----------------|
| Phosphorus | P | 15 | 30.97 | 31 | Phosphorus-31 | 15 | 15 | 31 - 15 = 16 |

Now complete for others.

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#### Aluminum

- Chemical Symbol: Al
- Atomic Number: 13
- Atomic Mass: ~26.98
- Mass Number: usually 27 (most common isotope)
- Isotopic Notation: Aluminum-27
- # of protons: 13
- # of electrons: 13 (neutral atom)
- # of neutrons: 27 - 13 = 14

---

#### Potassium

- Chemical Symbol: K
- Atomic Number: 19
- Atomic Mass: ~39.10
- Mass Number: 39 (common isotope)
- Isotopic Notation: Potassium-39
- # of protons: 19
- # of electrons: 19
- # of neutrons: 39 - 19 = 20

---

#### Argon

- Chemical Symbol: Ar
- Atomic Number: 18
- Atomic Mass: ~39.95
- Mass Number: 40 (common isotope)
- Isotopic Notation: Argon-40
- # of protons: 18
- # of electrons: 18
- # of neutrons: 40 - 18 = 22

---

#### Lead

- Chemical Symbol: Pb
- Atomic Number: 82
- Atomic Mass: ~207.2
- Mass Number: 208 (most stable isotope)
- Isotopic Notation: Lead-208
- # of protons: 82
- # of electrons: 82
- # of neutrons: 208 - 82 = 126

> Note: Lead has several isotopes, but Pb-208 is the most common stable one.

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Now fill the table:

| Element | Chemical Symbol | Atomic Number | Atomic Mass | Mass Number | Isotopic Notation | # of protons | # of electrons | # of neutrons |
|---------------|------------------|----------------|--------------|---------------|--------------------|---------------|----------------|----------------|
| Phosphorus | P | 15 | 30.97 | 31 | Phosphorus-31 | 15 | 15 | 16 |
| Aluminum | Al | 13 | 26.98 | 27 | Aluminum-27 | 13 | 13 | 14 |
| Potassium | K | 19 | 39.10 | 39 | Potassium-39 | 19 | 19 | 20 |
| Argon | Ar | 18 | 39.95 | 40 | Argon-40 | 18 | 18 | 22 |
| Lead | Pb | 82 | 207.2 | 208 | Lead-208 | 82 | 82 | 126 |

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Question 21: Name these atoms with their isotopic name

We have three diagrams showing nuclei with protons (+) and neutrons (no charge shown).

Each circle represents a nucleon.

#### First diagram:
- 4 protons (+)
- 4 neutrons (no + sign)
- Total nucleons: 8
- Protons = 4 → element is Beryllium (Be), atomic number 4
- Mass number = 8
- Isotopic name: Beryllium-8

But Be-8 is unstable, but we name it anyway.

✔ Beryllium-8

#### Second diagram:
- Count protons: 6 (+ signs)
- Neutrons: 6 (no + signs)
- Total = 12
- Protons = 6 → Carbon (C)
- Isotopic name: Carbon-12

✔ Carbon-12

#### Third diagram:
- Protons: 8 (+ signs)
- Neutrons: 8 (no + signs)
- Total = 16
- Protons = 8 → Oxygen (O)
- Isotopic name: Oxygen-16

✔ Oxygen-16

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✔ Final Answers:

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19. Label each part:

- Arrow to 25: Atomic Number
- Arrow to Mn: Chemical Symbol
- Arrow to Manganese: Element Name
- Arrow to 54.94: Atomic Mass

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20. Completed Table:

| Element | Chemical Symbol | Atomic Number | Atomic Mass | Mass Number | Isotopic Notation | # of protons | # of electrons | # of neutrons |
|---------------|------------------|----------------|--------------|---------------|--------------------|---------------|----------------|----------------|
| Phosphorus | P | 15 | 30.97 | 31 | Phosphorus-31 | 15 | 15 | 16 |
| Aluminum | Al | 13 | 26.98 | 27 | Aluminum-27 | 13 | 13 | 14 |
| Potassium | K | 19 | 39.10 | 39 | Potassium-39 | 19 | 19 | 20 |
| Argon | Ar | 18 | 39.95 | 40 | Argon-40 | 18 | 18 | 22 |
| Lead | Pb | 82 | 207.2 | 208 | Lead-208 | 82 | 82 | 126 |

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21. Isotopic Names:

1. Beryllium-8
2. Carbon-12
3. Oxygen-16

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