which laboratory activity involves a chemical change?\no leaving a copper penny in vinegar until it turns…

which laboratory activity involves a chemical change?\no leaving a copper penny in vinegar until it turns green\no boiling saltwater for several minutes until only solid salt remains\no extracting iron filings from a sand mixture using a magnet\no crushing a rock with a hammer to extract mineral deposits

which laboratory activity involves a chemical change?\no leaving a copper penny in vinegar until it turns green\no boiling saltwater for several minutes until only solid salt remains\no extracting iron filings from a sand mixture using a magnet\no crushing a rock with a hammer to extract mineral deposits

Answer

Answer:

A. leaving a copper penny in vinegar until it turns green

Brief Explanations:

A chemical change forms new substances. Copper in vinegar reacts to form green - copper acetate. Boiling saltwater is evaporation (physical), extracting iron with magnet is physical separation, crushing rock is a physical change of size and shape.