What does the law of constant composition say about different samples of the same compound?

1. A compound has a fixed recipe rather than a variable one. 2. The law of constant composition says all samples of a compound are made of the same elements in the same proportion or ratio. 3. Every water molecule has two hydrogen atoms for every one oxygen atom. 4. That also fixes the mass proportion of each element inside the compound. 5. Two elements can still form more than one compound, each with its own fixed ratio. 6. Hydrogen and oxygen also form hydrogen peroxide, which has a different fixed ratio from water. 7. Sample mass is not fixed at all, since you can weigh out as much or as little as you like. _Source: Siyavula Physical Sciences Grade 10 (Everything Science, CC BY 4.0), Chapter 13: Physical and chemical change_