Hydrogen is the lightest element known so far.

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Statement**: The statement we need to evaluate is "Hydrogen is the lightest element known so far."

2. **Identifying Hydrogen's Atomic Structure**: To determine if this statement is true, we need to analyze the atomic structure of hydrogen. A hydrogen atom consists of:
- 1 proton in the nucleus
- 1 electron in its outer orbit
- 0 neutrons

3. **Determining Atomic Mass**: The atomic mass of hydrogen is approximately 1 atomic mass unit (amu). The exact mass is 1.00794 amu, but for simplicity, we can refer to it as 1 amu.

4. **Conclusion on Lightness**: Since hydrogen has the lowest atomic mass of all elements (1 amu), it is indeed the lightest element known.

5. **Final Evaluation of the Statement**: Therefore, the statement "Hydrogen is the lightest element known so far" is true.

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