pH Levels Worksheet - Identify acids and bases using a colorful pH scale.

Let's solve this pH Levels worksheet step by step. The goal is to:

1. Understand the pH scale.
2. Identify whether each substance is acidic, neutral, or basic.
3. Place each substance on the correct color level of the pH scale based on its typical pH value.

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🔬 Step 1: Understanding the pH Scale

The pH scale ranges from 0 to 14, where:
- 0–6: Acidic (red to yellow)
- 7: Neutral (green)
- 8–14: Basic (alkaline) (blue to purple)

The colors on the scale go from:
- Red → Orange → Yellow → Green → Blue → Purple
- This corresponds to acidic → neutral → basic

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🧪 Step 2: Typical pH Values of Each Substance

Let’s list the substances and their approximate pH values:

| Substance | Approximate pH | Classification |
|-------------------|----------------|----------------|
| Blood | 7.4 | Basic |
| Lemon | 2.0–2.5 | Acidic |
| Gastric Acid | 1.5–3.5 | Acidic |
| Tomato | 4.0–4.5 | Acidic |
| Coffee | 5.0 | Slightly Acidic|
| Ammonia Acid | ~11.5 | Basic |
| Bleach | 12.5 | Basic |
| Battery Acid | 0.8–1.5 | Strongly Acidic|
| Soda (Cola) | 2.5 | Acidic |
| Soap | 9.0–10.0 | Basic |
| Water | 7.0 | Neutral |
| Drain Cleaner | 13.5–14.0 | Strongly Basic |
| Milk | 6.5–6.8 | Slightly Acidic|
| Stomach Tablets | ~8.0 | Basic |
| Baking Soda | 8.0–9.0 | Basic |

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🎯 Step 3: Assigning Colors & Positions on the Scale

Now we match each item to the correct color band on the pH scale.

#### 🔴 Red (Strongly Acidic): pH 0–2
- Battery Acid (pH ~1)
- Gastric Acid (pH ~2)

#### 🟡 Orange/Yellow (Moderately Acidic): pH 3–6
- Lemon (pH ~2.5) – slightly above red, but close
- Soda (pH ~2.5) – same as lemon
- Tomato (pH ~4.5)
- Coffee (pH ~5)
- Milk (pH ~6.5) – near neutral, but still acidic
- Stomach Tablets (pH ~8) – wait! That's basic → should be in blue/green

Wait — let’s double-check: Stomach tablets like antacids are basic, so they belong in blue/green.

Let’s organize properly.

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✔ Correct Placement on the Scale

We’ll go from top (most acidic) to bottom (most basic):

#### 🔴 Red (pH 0–2) – Very Acidic
- Battery Acid (pH ~1)
- Gastric Acid (pH ~1.5–3.5) → place at top end

#### 🟠 Orange (pH 3–4) – Acidic
- Lemon (pH ~2.5) → may be just below red, but often placed here
- Soda (pH ~2.5) → same
- Tomato (pH ~4.5) → near orange/yellow border

#### 🟡 Yellow (pH 5–6) – Mildly Acidic
- Coffee (pH ~5)
- Milk (pH ~6.5) → edge of yellow/green

#### 🟢 Green (pH 7) – Neutral
- Water (pH 7) → center green

#### 🟦 Blue (pH 8–10) – Mildly Basic
- Blood (pH ~7.4) → just above neutral → light blue
- Soap (pH ~9)
- Baking Soda (pH ~8.5)
- Stomach Tablets (pH ~8)

#### 🔵 Dark Blue/Purple (pH 11–14) – Strongly Basic
- Ammonia (pH ~11.5)
- Bleach (pH ~12.5)
- Drain Cleaner (pH ~13.5–14)

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🖼️ Final Placement Guide

Here’s how you should cut out and place each image on the colored scale:

#### 🔴 Top (Red/Orange – Acidic)
- Battery Acid → Top red
- Gastric Acid → Just below battery acid
- Lemon → Orange zone
- Soda → Orange zone
- Tomato → Yellow-orange
- Coffee → Yellow
- Milk → Yellow-green border

#### 🟢 Center (Green – Neutral)
- Water → Middle green (pH 7)

#### 🟦 Bottom (Blue/Purple – Basic)
- Blood → Light blue (just above neutral)
- Soap → Medium blue
- Baking Soda → Medium blue
- Stomach Tablets → Medium blue
- Ammonia → Dark blue
- Bleach → Deep blue
- Drain Cleaner → Purple (strongest base)

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✔ Label the Scale

On the left side of the scale, label:

- Top (Red): "Strongly Acidic"
- Middle (Green): "Neutral"
- Bottom (Purple): "Strongly Basic"

Also, label the scale with numbers:
- 0 at the top (red)
- 7 in the middle (green)
- 14 at the bottom (purple)

You can write:
```
pH Scale:
0 (Strongly Acidic) → 7 (Neutral) → 14 (Strongly Basic)
```

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📝 Summary for Student Worksheet

Instructions:
1. Cut out all the pictures.
2. Glue them on the corresponding color bar based on their pH.
3. Label the scale:
- Top: "Acidic" or "Low pH"
- Middle: "Neutral"
- Bottom: "Basic" or "High pH"

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🧩 Example Placement (from top to bottom):

| Color Zone | Substance |
|------------|------------------------|
| Red | Battery Acid, Gastric Acid |
| Orange | Lemon, Soda |
| Yellow | Tomato, Coffee, Milk |
| Green | Water |
| Blue | Blood, Soap, Baking Soda, Stomach Tablets |
| Purple | Ammonia, Bleach, Drain Cleaner |

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✔ Final Answer:
Place each substance according to its pH value on the color-coded scale, from most acidic (red) at the top to most basic (purple) at the bottom. Use the chart above to guide placement.

This activity helps students visualize acidity and basicity through real-life examples and the pH scale.