Educational worksheet identifying molecules in everyday objects and biological structures.

Let's solve this step-by-step.

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Task:

Put an X next to the things on the list that are made up of one or more molecules.

We need to determine which items are composed of molecules. Remember:

> A molecule is formed when two or more atoms are chemically bonded together. Molecules can be simple (like H₂O) or complex (like DNA).
> Atoms are not molecules unless they are bonded to other atoms.
> Subatomic particles like protons and electrons are not molecules.
> Living things, cells, tissues, and objects are made of molecules (like proteins, lipids, carbohydrates, etc.).

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✔ Rule/Reasoning:

- Molecules = Atoms bonded together.
- Anything made of matter (except subatomic particles) is made of molecules.
- Cells, organisms, food, liquids, gases — all are made of molecules.
- Atoms alone are not molecules unless bonded.
- Subatomic particles (protons, electrons, atomic nucleus) are not molecules.

---

Now, let’s go through the list:

#### Left Column:
1. bread → made of starch, proteins, water — ✔ X
2. protons → subatomic particles — ✘
3. water → H₂O molecule — ✔ X
4. atomic nucleus → made of protons and neutrons — ✘
5. brain cell → a cell made of molecules — ✔ X
6. milk → contains fats, proteins, sugars — ✔ X
7. egg → contains proteins, fats, water — ✔ X
8. atom → single atom ≠ molecule — ✘
9. seed → living thing made of cells → made of molecules — ✔ X
10. bacteria → living organism → made of molecules — ✔ X
11. skin → tissue made of cells → made of molecules — ✔ X

#### Right Column:
1. DNA → large molecule — ✔ X
2. cell membrane → made of phospholipids and proteins — ✔ X
3. cloud → made of water droplets (H₂O molecules) — ✔ X
4. oil → made of hydrocarbon molecules — ✔ X
5. worm → living organism — ✔ X
6. protein → a molecule — ✔ X
7. sugar → sucrose, glucose — molecules — ✔ X
8. flower → plant part — made of cells → molecules — ✔ X
9. chromosome → made of DNA and proteins — ✔ X
10. blood → liquid made of plasma, cells, proteins — ✔ X
11. leaf → plant part — made of cells → molecules — ✔ X
12. air → mixture of gas molecules (O₂, N₂, CO₂) — ✔ X
13. mushroom → fungus — made of cells → molecules — ✔ X
14. fruit → plant organ — made of cells → molecules — ✔ X

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✔ Final Answer with X's:

```
____ bread ___X_ DNA
____ protons ___X_ cell membrane
____ water ___X_ cloud
____ atomic nucleus ___X_ oil
____ brain cell ___X_ worm
____ milk ___X_ protein
____ egg ___X_ sugar
____ atom ___X_ flower
____ seed ___X_ chromosome
____ bacteria ___X_ blood
____ skin ___X_ leaf
___X_ air
___X_ mushroom
___X_ fruit
```

Wait — we missed some spacing. Let's format it correctly:

```
___X_ bread ___X_ DNA
____ protons ___X_ cell membrane
___X_ water ___X_ cloud
____ atomic nucleus ___X_ oil
___X_ brain cell ___X_ worm
___X_ milk ___X_ protein
___X_ egg ___X_ sugar
____ atom ___X_ flower
___X_ seed ___X_ chromosome
___X_ bacteria ___X_ blood
___X_ skin ___X_ leaf
___X_ air
___X_ mushroom
___X_ fruit
```

Note: The last four items (air, mushroom, cell nucleus, fruit) were listed in separate columns. Let's correct:

Actually, from the image layout:
- "air", "mushroom", "cell nucleus", "fruit" are at the bottom, likely under the right column.

But "cell nucleus" was listed as:
```
____ leaf ____ air
____ cell nucleus ____ mushroom
____ fruit
```

So:

- cell nucleus → made of molecules (proteins, DNA, etc.) — ✔ X
- fruit → made of cells → molecules — ✔ X

So final list:

```
___X_ bread ___X_ DNA
____ protons ___X_ cell membrane
___X_ water ___X_ cloud
____ atomic nucleus ___X_ oil
___X_ brain cell ___X_ worm
___X_ milk ___X_ protein
___X_ egg ___X_ sugar
____ atom ___X_ flower
___X_ seed ___X_ chromosome
___X_ bacteria ___X_ blood
___X_ skin ___X_ leaf
___X_ air
___X_ mushroom
___X_ cell nucleus
___X_ fruit
```

Wait — atom is not a molecule → no X
atomic nucleus → not a molecule → no X
protons, electrons → subatomic → not molecules

So corrections:

- atom → ✘
- atomic nucleus → ✘
- protons → ✘
- electrons → ✘

Also, check if "electron" was listed.

Looking back:

At the bottom:
```
____ leaf ____ air
____ cell nucleus ____ mushroom
____ fruit
```

And earlier:
```
____ electrons ____ cell nucleus
```

Ah! So "electrons" is listed:

```
____ electrons ____ cell nucleus
```

So:

- electrons → subatomic particle → ✘
- cell nucleus → made of molecules → ✔ X

---

✔ Corrected Final List:

```
___X_ bread ___X_ DNA
____ protons ___X_ cell membrane
___X_ water ___X_ cloud
____ atomic nucleus ___X_ oil
___X_ brain cell ___X_ worm
___X_ milk ___X_ protein
___X_ egg ___X_ sugar
____ atom ___X_ flower
___X_ seed ___X_ chromosome
___X_ bacteria ___X_ blood
___X_ skin ___X_ leaf
____ electrons ___X_ air
___X_ cell nucleus ___X_ mushroom
___X_ fruit
```

Wait — "electrons" is under the same line as "cell nucleus"? Let's reconstruct properly.

From the original:

```
____ leaf ____ air
____ cell nucleus ____ mushroom
____ fruit
```

And above:

```
____ electrons ____ cell nucleus
```

That seems duplicated. Probably a formatting issue.

Likely intended layout:

```
____ leaf ____ air
____ electrons ____ mushroom
____ cell nucleus ____ fruit
```

But that doesn't make sense.

Looking at the original:

It says:
```
____ leaf ____ air
____ cell nucleus ____ mushroom
____ fruit
```

And before that:
```
____ electrons ____ cell nucleus
```

Wait — so “electrons” and “cell nucleus” are on the same line?

Possibly:

```
____ electrons ____ cell nucleus
____ leaf ____ air
____ mushroom ____ fruit
```

But that’s messy.

Best interpretation: There are two columns of items.

From top to bottom:

Left Column:
- bread
- protons
- water
- atomic nucleus
- brain cell
- milk
- egg
- atom
- seed
- bacteria
- skin
- electrons

Right Column:
- DNA
- cell membrane
- cloud
- oil
- worm
- protein
- sugar
- flower
- chromosome
- blood
- leaf
- air
- mushroom
- cell nucleus
- fruit

So “electrons” is in the left column, “cell nucleus” is in the right column.

So:

- electrons → subatomic → ✘
- cell nucleus → made of molecules → ✔ X

Final list:

✔ Marked Answers:

```
___X_ bread ___X_ DNA
____ protons ___X_ cell membrane
___X_ water ___X_ cloud
____ atomic nucleus ___X_ oil
___X_ brain cell ___X_ worm
___X_ milk ___X_ protein
___X_ egg ___X_ sugar
____ atom ___X_ flower
___X_ seed ___X_ chromosome
___X_ bacteria ___X_ blood
___X_ skin ___X_ leaf
____ electrons ___X_ air
___X_ mushroom
___X_ cell nucleus
___X_ fruit
```

Wait — “electrons” is in the left column, so it should be:

```
____ electrons
```

And “cell nucleus” is in the right column, so:

```
___X_ cell nucleus
```

But “cell nucleus” is already listed in the right column.

So final clean version:

---

✔ Final Answer:

```
___X_ bread ___X_ DNA
____ protons ___X_ cell membrane
___X_ water ___X_ cloud
____ atomic nucleus ___X_ oil
___X_ brain cell ___X_ worm
___X_ milk ___X_ protein
___X_ egg ___X_ sugar
____ atom ___X_ flower
___X_ seed ___X_ chromosome
___X_ bacteria ___X_ blood
___X_ skin ___X_ leaf
____ electrons ___X_ air
___X_ mushroom
___X_ cell nucleus
___X_ fruit
```

---

✔ Explanation of Thinking:

I used the following rule:

> An item is made of molecules if it is composed of atoms that are chemically bonded together, or if it is a larger structure made of such molecules.

Here’s how I applied it:

- Molecules: Water (H₂O), DNA, protein, sugar, oil — all are molecules.
- Made of molecules: Bread, milk, egg, brain cell, bacteria, skin, seed, worm, flower, leaf, fruit, mushroom, blood, cloud, air — all are made of cells, tissues, or substances composed of molecules.
- Not made of molecules:
- Protons, electrons, atomic nucleus — these are subatomic particles or collections of subatomic particles, not molecules.
- Atom — a single atom is not a molecule unless bonded to another atom.

Thus, only atoms and subatomic particles are not made of molecules.

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✔ Final Rule Summary:

> Any object or substance that is made of matter (except individual atoms or subatomic particles) is made of one or more molecules.
> Molecules are formed when atoms bond together.
> Everything larger than an atom or subatomic particle (like cells, organisms, food, liquids, gases) is made of molecules.

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✔ Answer Complete.