Is the law of constant composition true for all types of compounds ? Explain why or why not.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Law of Constant Composition:**
- The law of constant composition states that a chemical compound always contains the same elements in the same proportion by mass. This means that no matter the source or method of preparation, the ratio of the masses of the elements in a compound remains constant.

2. **Identifying the Types of Compounds:**
- Compounds can be composed of different isotopes of the same element. Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons, leading to different atomic masses.

...