Science physical changes
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Is the following a physical property, physical change, chemical property, or chemical change? Water boiling
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Physical change
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Is the following a physical property, physical change, chemical property, or chemical change? Gold is shiny and very dense
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Physical Property
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Is the following a physical property, physical change, chemical property, or chemical change? Fireworks on the 4th of July
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Chemical Change or Chemical Reaction They are both the same thing
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Is the following a physical property, physical change, chemical property, or chemical change? Paper is flammable
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Chemical Property Flammability is the ability of something to take flame or the ability to burn.
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Is the following a physical property, physical change, chemical property, or chemical change? Adding salt to water to lower the freezing point of water.
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Physical Property Dissolving is physical
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Define physical change.
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Does not create a new substance, can return to its original form, still the same substance, and only 0 or 1 sign of a chemical reaction.
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Why is melting a bicycle frame only a physical change?
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only a phase change
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What are 3 examples of a physical change?
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New color, new size, new shape, different state of matter, disappeared, melted, new mass, new volume, etc.
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How can a change of color be a physical change?
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Dye, paint, color, etc.
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How could you SHOW that dissolving salt in water is the result of a physical change?
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Evaporate the water to change it back or taste it and it is still the same substance
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The burning of a candle will show what signs of a chemical reaction?
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Unexpected color change (the wick turns black), gas produced, flames, exothermic heat exchange, slight sound produced, and a change in density
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Define chemical change.
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Chemical changes occurs when 2 substances react to form a new substance, can't return to its original state, shows 2 or more signs of a chemical reaction, new substance with new and different properties.
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What sign of a chemical reaction occurs when 2 liquids form a solid?
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precipitate formed
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For the signs of a chemical reaction, when we have a gas produced or precipitate formed, we will always have this sign?
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A change in density.
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How is the statue of liberty an example of a chemical change?
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Oxidation of copper - copper turns green after being exposed to air
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What is a chemical property of wood?
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Flammable
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Give two examples of a physical change that can be done to paper.
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Cut, tear, rip, crumple, fold, roll, punch holes in, color on it, write on it, etc.
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What is the name for the reaction where shiny metals such as silver or brass combine with chemicals in the air such as sulfur and turn black?
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Tarnishing
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What is the difference between exothermic and endothermic?
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Exothermic is heat released so it feels hot. Endothermic is when heat is absorbed so it feels cool.
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Name 2 chemical changes a CSI agent uses for solving crimes.
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*Luminol chemically glows on blood *Super glue vapors turn white on finger prints
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Physical or Chemical? Paper folding
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Physical Change - folding or changing shape
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Physical or Chemical? Tarnishing penny
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Chemical Change - unexpected color change, bubbles, new substance formed
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Physical or Chemical? Ice cube melting
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Physical Change - just a phase change
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Physical or Chemical? Leaves changing color
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Chemical Change - unexpected color change, no longer producing chlorophyll
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Physical or Chemical? Fried egg
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Chemical Change - cooked, needed heat, gave off gas, odor, unexpected color change
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What are the signs of a chemical reaction?
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1. Unexpected color change 2. gas given off 3. flames/burning 4. heat change- exothermic or endothermic 5. sound 6. change in density 7. formation of a precipitation- combining 2 liquids to form a chunky one
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What is an independent variable
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the single thing I CHANGE in the experiment
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What is a dependent variable
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What you are measuring creates the data
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What is a control
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The normal conditions without changes
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What is a constant
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The data that needs to stay the same
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What does PHEOC stand for
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Problem, Hypothesis, experiment, Observation, Conclusion
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Physical Change
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1. Can be changed back 2. Similar properties 3. same substance
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Chemical Change
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1. Can't be changed back 2. Different properties 3. new substance
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Matter
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anything that has mass or takes up space
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Chemistry
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study of matter and how matter changes
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Substance
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single kind of matter that is pure, meaning it always has a specific makeup
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I can adjust the height of the flame by adjusting the
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gas adjustment valve
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I can adjust the temperature of a flame by adjusting the
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air intake barrel
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T or F: A chemical change is the same as a chemical reaction
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True
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T or F: The ability of a substance to support burning is called flammability
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True
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T or F: A chemical property and a chemical change are the same thing
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False, chemical change is the substance changing and chemical property is the ability to change
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independent vs dependent: Different types of radiation were used to determine which best kill microorganisms on strawberries
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Independent: Type of radiation Dependent: microorganisms
