Tell whether the following terms are associated with a physical change of matter, a chemical change of matter, or if they are both. Explain each change. Explain how those labeled as both can be both. Decomposition- Chemical- breaking down of a substance into two or more different substances. Food decomposes in our bodies while we eat, gas is given off. Temperature- Physical- changing temps can make a state change occur. Water boiling becomes water vapor Freezing- Physical-lowering of temperature becomes solid-water becoming ice. Oxidizing- Chemical-When a substance reacts with oxygen in a chemical bond. Tarnishing silver, rusting iron and green copper carbonate are examples of oxidation. Replacement- Chemical-2H₂O₂ is hydrogen peroxide, it reacts with oxygen in the air and becomes 2H₂O and O₂, water and oxygen. Surface area- Physical-measuring the outside of substances doesn’t change the chemical formula shape change. Density- Both- If the density of the matter doesn’t change, it is physical, like cutting carrots. If the density changes, you have created a new substance. Mixing an acid and a base makes a salt. Texture- Both-cutting your hair could change the texture and it is physical, or combining sodium metal with chlorine gas makes table salt and the texture changes. Endothermic- Chemical-combining 2 or more substances to get a new substance and heat and/or light are taken into the reaction, the substance gets cooler. Synthesis-Chemical-2 or more substances join to a new substance. Sodium + Chlorine=salt Rusting-Chemical-iron oxidizes to make rust. Color- Both-Physical water getting cloudy when salt dissolves in it, (physical) or Food burning turns black as carbon forms (Chemical) States of matter- Both- physical-ice melting to water, chemical-when 2 liquids join to make a solid precipitate. Mostly physical Precipitate- Chemical, the formation of a solid from 2 liquids through synthesis. Exothermic- Chemical-combining 2 or more substances creates a new substance giving off heat and/or light. Shape- Both- squishing playdough is physical, but decomposing grass is chemical. BurningChemical-creating a new substance, carbon on an existing substance. Gas bubbles- Chemical-Gas bubbles are a sign of decomposition and a gas releasing to the air. Melting-Physical-temp change where the substance doesn’t change.