Which of the following materials is a substance. air gasoline stainless steel or silver

Substances are matter that has uniform and constant composition: same number and kind of atoms bonded in the same way.The substances are compounds or elements.From the options given, only silver is a substance, because it is an element, and all silver materials have only silver atoms. Air is a mixture of different gases,which may varies in composition; gasoline is a mixture of liquids which may change in composition; steel is an alloy (a mixture of compounds and elements) which varies in composition. So, the answer is Silver.

Hno3(aq) → h+(aq) + no3−(aq). picture ii best represents the strong acid hno3. strong acids are strong electrolytes

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