Mark the incorrect statement

Options

A. Melting of wax is a physical change while burning of wax in a candle is a chemical change.
B. Metals expand on heating while contract on cooling. Both are physical changes.
C. Composition of matter changes during a chemical change while it remains same during a physical change
D. High and low tides in sea are the examples of non-periodic changes while growth of a tree is a periodic change.

Explanation

To solve the question of marking the incorrect statement, let's analyze each statement provided in the context of physical and chemical changes.

### Step-by-Step Solution:

1. **Understanding Physical Change**:
- The first statement mentions that the melting of wax is a physical change, while the burning of wax in a candle is a chemical change.
- **Analysis**: Melting wax changes its state from solid to liquid but does not create a new substance. Therefore, this statement is **correct**.

2. **Understanding Chemical Change**:
- The second statement discusses the burning of wax. When wax burns, it reacts with oxygen to form carbon dioxide and water, which are new substances.
- **Analysis**: Since new substances are formed during burning, this statement is also **correct**.

3. **Composition of Matter**:
- The third statement states that the composition of matter changes during a chemical change while it remains the same during a physical change.
- **Analysis**: This is true because during a chemical change, new substances are formed, indicating a change in composition. Thus, this statement is **correct**.

4. **Periodic vs Non-Periodic Changes**:
- The fourth statement claims that high and low tides in the sea are examples of non-periodic changes, while the growth of a tree is a periodic change.
- **Analysis**: High and low tides are actually periodic changes, occurring at regular intervals due to gravitational effects. The growth of a tree can be considered a more gradual process but can also be seen as periodic depending on the context (e.g., seasonal growth). Therefore, this statement is **incorrect**.

### Conclusion:
The incorrect statement is the fourth one, which misclassifies high and low tides as non-periodic changes.

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