Physical and Chemical Changes

Topic Page

Questions

• How can you increase the speed of a chemical change?
• What is a chemical change?
• How are physical changes different from chemical changes?
• Do chemical changes involve energy?
• What is a physical change?
• Are physical changes reversible?
• Question #d9d76
• Is the protonolysis reaction of sulfuric acid in aqueous solution an example of chemical change?
• Question #76744
• What are the chemical changes of smores?
• What are the signs of a chemical change?
• Is milk souring a physical or chemical change?
• Question #5fe4a
• Is combustion a physical or chemical change? Why?
• Can a chemical change alter the total number of atoms?
• A light green powder is heated in a test tube. A gas is given off, and the solid becomes black. Was the change physical or chemical, and is the green powder an element, a compound, or a mixture?
• Question #72caa
• What might happen to a heated beaker made from glass that does not contain boron if the beaker were placed in a pan of ice water?
• What chemical change did the Statue of Liberty likely undergo?
• Do atoms/molecules change their arrangement during a physical change?
• Why is breaking down a compound into its elements considered a chemical change?
• Question #39e19
• Question #47ae6
• What is the chemical formula of sulphuric acid?
• If a box of crayons is left in a hot car on a summer afternoon, what change would you expect to observe in the crayons?
• Question #4ed7e
• Why is the rusting of an iron pole not a physical change?
• Question #d38ee
• A color change happens during an experiment mixing two liquids. Is this a physical change or chemical change?
• What is the component which dissolves in a solution called?
• Is a piece of copper cut in half a physical or chemical change?
• Is salt dissolving in water physical or chemical change?
• Is the freezing of mercury a reversible or irreversible physical change?
• Why are new properties observed during a change of state not signs of a chemical change?
• What is an example of a chemical change?
• In an experiment, a colour change is observed, and also observed is prolonged bubbling. Is this a chemical change?
• What name is given to substances that resist changes in pH?
• A firefly emits light. Is this a physical change?
• Is water boiling at 100 degrees Celsius a physical change?
• Is boiling water a physical or chemical change?
• Is cooking an egg an example of a physical or chemical change?
• Milk turns sour. Is this a chemical or physical change?
• Salt dissolves in water. Is this a chemical or physical change?
• Water boils. Is this a chemical or physical change?
• What are four possible clues that a a chemical change has taken place?
• How does a chemical change affect the composition of matter?
• What occurs when calcium chloride is reacted with sodium bisulfate?
• How did adding salt to ice change its freezing point?
• Why does an egg change color and texture when heated?
• Which property of physical changes explains why matter is conserved in a physical change?
• How can we tell if a chemical change has taken place?
• Is it correct to say that dissolving i a packet of juice powder in water makes a new substance, fruit punch, and so it must not be a physical change?
• Why is making play dough a physical change?
• Is distillation a physical change?
• Is evaporation a physical change?
• Is corrosion a physical change?
• Is sublimation a physical change?
• Is sublimation a chemical change?
• Is corrosion a chemical change?
• Is distillation a chemical change?
• Is evaporation a chemical change?
• Is evaporation a chemical or physical change?
• Is distillation a chemical or physical change?
• Is corrosion a chemical or physical change?
• Is sublimation a chemical or physical change?
• What are 3 examples of a chemical change?
• Is tarnishing (blackening) of silver a useful or harmful chemical change? Why?
• Is the production of heat or light evidence that a chemical change may have occurred?
• Is color change evidence that a chemical or physical change may have occurred?
• Is hammering a physical change?
• Is rotting wood a chemical or physical change?
• Is iron rust an example of a physical or chemical change?
• When sodium hydroxide dissolves in water is it a chemical or physical change?
• Is boiling point considered a physical or chemical change?
• Is a reaction with a base to form water physical or chemical change?
• Are reactions with water to form a gas physical or chemical changes?
• Is melting point considered a physical or chemical change?
• Would the reaction between dihydrogen and sodium hydroxide to give sodium and water be considered a chemical change?
• You go on vacation for a week and leave a bowl of fruit on the table. When you return you observe the pieces of fruit. What clues would indicate that the fruir has undergone a chemical change?
• Is making glue an example ot a chemical change or a physical change? How do you know?
• Question #9ab33
• What is changed when matter undergoes a physical change?
• What are examples of physical changes? Chemical changes?
• Is chemical change irreversible?
• Is tarnishing considered a physical or chemical change?
• Is burning considered a physical or chemical change?
• It is said chemical and physical properties are closely linked. Why does a chemical change also cause a change in physical properties?
• What speeds up chemical changes?
• Is dissolution a chemical change?
• Question #e57dc
• What characterizes chemical change?
• Question #98920
• How might you tell whether or not your toothpaste contained calcium carbonate, #CaCO_3#, or perhaps baking soda, #NaHCO_3#, without looking at the ingredients label?
• Is the explosion of fireworks a physical or chemical change?
• Michael mixes two chemicals together in a beaker. The chemicals change color, and the beaker heats up quickly. What kind of change most likely occurred?
• Is a bread being baked a physical or chemical change?
• Why are chemical changes different from physical changes?
• Is bubbling the sign of a chemical or physical change?
• What kind of changes (chemical or physical) do chefs use make to food?
• Is melting crayons is an example of a chemical or physical change?
• What are 5 examples of chemical changes?
• What is the differences between physical changes and chemical changes?
• Is adding sugar to lemonade a physical or chemical change?
• Is removing salt from water by evaporation considered a physical or chemical change?
• What are chemical changes and physical changes?
• What are the changes that occur inside a helium balloon as it rises from sea level?
• What are the five "clues" that a chemical change has occurred?
• Rusting metal is an example of what type of change?
• How can you tell that a hamburger is undergoing a chemical change when you cook it?
• What physical changes happen to water as it freezes?
• Question #cf954
• Question #b6df9
• Question #7e2d2
• Question #9747b
• Question #c40b2
• Is hydrogen and oxygen gas combining to form #H_2O# a chemical or physical change?
• When methanol is burned and leaves a residue is this a chemical or pyhsical change?
• An aspirin is crushed into fine power. Is this a physical or chemical change?
• Is baking cookies a physical or chemical change?
• Is cutting hair a physical or chemical change?
• Question #87413
• How is #"chemical change"# differentiated from #"physical change"#?
• What doesn't change during a physical change?
• The dissolving of which salt will produce both a physical and chemical change?
• Question #7b398
• When charcoal burns, it undergocs a chemical change that produces heat and light. Besides the charcoal, what is the other reactant in this chemical change?
• Question #862cc
• Is melting sugar a physical or chemical change?
• Rust is an example of what type of change?
• Question #ccc1e
• Question #1fa63
• Question #a18cd
• Does a lit candle provide an example of chemical change?
• Is deposition a physical or chemical change?
• Is condensation a physical or chemical change?
• Is evaporation a physical or chemical change?
• Question #2d4b8
• Is wood burning a physical or chemical change?
• What kind of reaction is represented by #2K + I_2 -> 2KI#?
• Question #3749a
• Question #ed5e2
• Question #2d155
• What term can be used to label the chemical change sodium cation undergoes after dissolving in water?
• #NH_4OH + HCl(aq) = NH_4Cl(aq) + H_2O(l)# no significant change can be noticed How to make sure that a reaction is really taking place ?
• Explain that magnetization of an iron nail is a physical change?
• Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what conditions do these grapes ferment? Is it a chemical or a physical?
• Question #f6876
• When baking soda is added to vinegar, it reacts vigorously, causing some fizzing and gas evolution. If a lit match is brought near the reaction flask, it is extinguished. What two key information help you identify this as a chemical change?
• The mass of a beaker containing a sample of water at 20°C was 109.44 g. After heating the sample to 60°C, the combined mass of the beaker and water was 109.08 g. Do these results contradict the law of conservation of mass?
• Question #68599
• Does freezing a substance change it?
• Why might a physical change require energy?