Classify each statement as an observation, a law, or a theory.
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\begin{array}{l}{\text { a. All matter is made of tiny, indestructible particles called atoms. }} \\ {\text { b. When iron rusts in a closed container, the mass of the container }} \\ {\text { and its contents do not change. }} \\ {\text { c. In chemical reactions, matter is neither created nor destroyed. }} \\ {\text { d. When a match burns, heat is released. }}\end{array}
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