Biology worksheet designed to test students' understanding of water's unique chemical properties.

Here is the completed Properties of Water Worksheet with explanations for each answer:

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Properties of Water Worksheet

1. The hydrogen and oxygen atoms are held together by ________ bonds.
✔ Answer: *hydrogen*
🔍 Explanation: Hydrogen bonds form between hydrogen atoms in one water molecule and oxygen atoms in neighboring molecules. These are weak bonds but play a crucial role in water's properties.

2. The electrons are not shared equally creating a ________ molecule.
✔ Answer: *polar*
🔍 Explanation: Oxygen is more electronegative than hydrogen, so it pulls electrons closer to itself, making the molecule polar — meaning it has a partial positive charge on hydrogen and a partial negative charge on oxygen.

3. The polarity of water allows it to ________ with most substances. Because of this, it is referred to as the ________.
✔ Answer: *combine*, *universal solvent*
🔍 Explanation: Water’s polarity enables it to dissolve many substances (especially ionic and polar compounds), earning it the title "universal solvent."

4. Water molecules stick to other water molecules. This property is called ________.
✔ Answer: *cohesion*
🔍 Explanation: Cohesion is the attraction between like molecules (water to water). It results from hydrogen bonding and helps water move upward in plants via capillary action.

5. Hydrogen bonds form between adjacent water molecules because the ________ charged hydrogen end of one water molecule attracts the ________ charged oxygen end of another water molecule.
✔ Answer: *positive*, *negative*
🔍 Explanation: The hydrogen atom (H) carries a partial positive charge, while the oxygen atom (O) carries a partial negative charge. Opposite charges attract, forming hydrogen bonds.

6. Water molecules stick to other water molecules, it is known as a ________ molecule.
✔ Answer: *sticky*
🔍 Explanation: Due to cohesion and hydrogen bonding, water behaves like a “sticky” substance, which contributes to its surface tension and ability to form droplets.

7. Water molecules stick to other materials due to its polar nature. This property is called ________.
✔ Answer: *adhesion*
🔍 Explanation: Adhesion is the attraction between unlike molecules (e.g., water and glass). This property helps water climb up narrow tubes or plant stems.

8. ________ creates the skin-like surface formed due to the polar nature of water.
✔ Answer: *Surface tension*
🔍 Explanation: Surface tension arises because water molecules at the surface are pulled inward by cohesive forces, creating a "skin" that allows small insects to walk on water.

9. Water has a ________ ________ ________, it can absorb a large amount of heat before a change in temperature takes place.
✔ Answer: *high specific heat*
🔍 Explanation: Water absorbs a lot of heat without a significant rise in temperature, helping regulate climate and body temperature.

10. ________ is when water changes from a liquid to a gas.
✔ Answer: *Evaporation*
🔍 Explanation: Evaporation occurs when water molecules gain enough energy to escape into the air as vapor.

11. ________ is when water changes from a gas to a liquid.
✔ Answer: *Condensation*
🔍 Explanation: Condensation happens when water vapor cools down and turns back into liquid (e.g., dew formation).

12. Substances that are attracted to water are referred to as ________ and are considered to be water loving.
✔ Answer: *hydrophilic*
🔍 Explanation: Hydrophilic substances interact well with water due to their polarity or charge.

13. Substances that are not attracted to water are referred to as ________ and are considered to be water fearing.
✔ Answer: *hydrophobic*
🔍 Explanation: Hydrophobic substances repel water; they are nonpolar and do not dissolve in water (e.g., oils).

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Word Bank Used:

- polar
- hydrophilic
- universal solvent
- evaporation
- cohesion
- adhesion
- negative
- sticky
- high specific heat
- surface tension
- condensation
- hydrophobic
- positive
- hydrogen
- combine

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14. Draw and label a water molecule. Identify the positive (+) and negative ends(-).

📝 Drawing Description (since we can't draw here):

```
H
|
O=H
```

Or better yet:

```
H
|
O
|
H
```

But correctly showing bent shape (about 104.5° angle):

```
H
\
O
/
H
```

✔ Labeling:
- Oxygen (O) → labeled with (-) (partial negative)
- Each hydrogen (H) → labeled with (+) (partial positive)

➡️ The oxygen end is negative, and the hydrogen ends are positive.

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Give the chemical formula for water.

✔ Answer: H₂O

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✔ Final Answer Summary:

| Question | Answer |
|--------|--------|
| 1 | hydrogen |
| 2 | polar |
| 3 | combine, universal solvent |
| 4 | cohesion |
| 5 | positive, negative |
| 6 | sticky |
| 7 | adhesion |
| 8 | Surface tension |
| 9 | high specific heat |
| 10 | Evaporation |
| 11 | Condensation |
| 12 | hydrophilic |
| 13 | hydrophobic |
| 14 | Draw H₂O with bent shape, O (-), H (+) |
| Formula | H₂O |

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