What are polymers? What is the role of a polymer?A large molecule made of smaller joined molecules that has qualities of durability, flexibility, elasticity, they take a long time to decompose, they can be natural or synthetic. Wool, silk, rubber, plastic, nylon, spandex. What is the Law of Conservation of Mass? How does this law affect mass in a closed system as opposed to an open system?Why does this law not apply when a system is open? States that mass in the universe can’t be created or destroyed, it changes form physically and chemically. In an open system, it is hard to measure the mass after changes occur because new matter can be added and gasses can escape. In a closed system, any changes that occur will not change the mass of the system. What are synthetic materials, and how are they different from organic materials? Give 5 examples of synthetic materials we use each day. Synthetic materials are man made, they can be processed chemically or by chemically altering natural materials. They are not found in nature, but can be processed by natural things. Styrofoam, plastic, polyester, nylon, spandex, synthetic rubber, teflon. Compare and contrast physical and chemical changes in matter. A physical change is any change in matter that doesn’t create a new substance, the chemical formula for what has changed stays the same, ex-Water freezing to ice is still H2O. A chemical change always creates a brand new substance with a new chemical formula. Ex-Carbon dioxide and water changes to glucose and oxygen during photosynthesis. They both can change the size, shape, color and texture of matter. Give 6 examples of physical changes of matter.Chopping wood, size change, scrambling an egg-shape change Breaking glass-shape, Ice melting-state change, Erasing ink with an eraser-texture change, blending fruit into a smoothie-state change. Give 6 examples of chemical changes of matter. Mixing an acid liquid with a base liquid to form a precipitate, like lemon juice in milk. Burning food changes some of the food particles to black carbon. Iron mixing with oxygen creates rust, called rusting and it’s a form of oxidation. Yeast decomposes dough when it rises. Animals digesting food. Photosynthesis changes Carbon dioxide and water to glucose and oxygen. 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.