Who discovered the concept of electric charge?

Options

A. Benjamin Franklin.
B. Michael Faraday.
C. Madam Curie.
D. J.J Thomson

Explanation

To answer the question "Who discovered the concept of electric charge?", we can follow these steps:

### Step 1: Understand the Historical Context
- The concept of electric charge was developed in the 18th century. It was a time when many scientific discoveries were being made regarding electricity.

**Hint:** Research the timeline of electricity discoveries to understand the contributions of different scientists.

### Step 2: Identify Key Figures
- The question provides four options: Benjamin Franklin, Michael Faraday, Madame Curie, and JJ Thompson. We need to evaluate who among them is credited with the discovery of electric charge.

**Hint:** Look into the contributions of each scientist to the field of electricity.

### Step 3: Analyze the Contributions
- **Benjamin Franklin**: He is known for his experiments with electricity, particularly his famous kite experiment where he collected electric charges from thunderstorms. He categorized electric charges into two types: positive and negative.

- **Michael Faraday**: He made significant contributions to electromagnetism and electrochemistry but did not discover the concept of electric charge itself.

- **Madame Curie**: She is known for her work on radioactivity and did not contribute to the concept of electric charge.

- **JJ Thompson**: He is known for discovering the electron and contributing to atomic theory, but he did not discover the concept of electric charge.

**Hint:** Focus on the specific contributions related to electric charge rather than broader contributions to electricity.

### Step 4: Conclude the Answer
- Based on the analysis, Benjamin Franklin is the correct answer as he was the first to discover and categorize electric charge into positive and negative types.

**Hint:** Summarize your findings to reinforce the conclusion.

### Final Answer
The concept of electric charge was discovered by **Benjamin Franklin**.