Iron, Oxygen, and Hydrogen are examples of which chemical category?

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Multiple Choice

Iron, Oxygen, and Hydrogen are examples of which chemical category?

Iron, oxygen, and hydrogen are examples of elements—substances made of only one kind of atom. Each cannot be broken down into simpler substances by ordinary chemical reactions. Iron is a metal composed of iron atoms; oxygen and hydrogen are commonly found as diatomic molecules (O2 and H2), but they are still the same element throughout. These are not mixtures, where different substances are physically combined, nor compounds, which are formed when two or more elements bond in fixed ratios. A compound like water is made from hydrogen and oxygen together, whereas these examples are pure elements—the basic building blocks of matter in chemistry.

Iron, oxygen, and hydrogen are examples of elements—substances made of only one kind of atom. Each cannot be broken down into simpler substances by ordinary chemical reactions. Iron is a metal composed of iron atoms; oxygen and hydrogen are commonly found as diatomic molecules (O2 and H2), but they are still the same element throughout. These are not mixtures, where different substances are physically combined, nor compounds, which are formed when two or more elements bond in fixed ratios. A compound like water is made from hydrogen and oxygen together, whereas these examples are pure elements—the basic building blocks of matter in chemistry.

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