Physical & Chemical Changes

1. Physical & Chemical Changes http://www.youtube.com/watch?v=NNcQX033V_M

2. Physical Changes In a physical change, the _____________ of a substance may change, but the bonds holding the atoms together in molecules and ions have _____ been broken and new bonds have been made. Physical changes are also accompanied by _________ changes. __________, ____________, ____________, and tearing are examples of physical changes. All changes of _________ are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

3. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have _____ been broken and new bonds have been made. Physical changes are also accompanied by _________ changes. __________, ____________, ____________, and tearing are examples of physical changes. All changes of _________ are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

4. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by _________ changes. __________, ____________, ____________, and tearing are examples of physical changes. All changes of _________ are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

5. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. __________, ____________, ____________, and tearing are examples of physical changes. All changes of _________ are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

6. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, ____________, ____________, and tearing are examples of physical changes. All changes of _________ are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

7. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, ____________, and tearing are examples of physical changes. All changes of _________ are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

8. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, grinding, and tearing are examples of physical changes. All changes of _________ are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

9. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, grinding, and tearing are examples of physical changes. All changes of state are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new ____________. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

10. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, grinding, and tearing are examples of physical changes. All changes of state are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new substances. _____________ is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

11. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, grinding, and tearing are examples of physical changes. All changes of state are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new substances. Dissolving is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to _________. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

12. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, grinding, and tearing are examples of physical changes. All changes of state are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new substances. Dissolving is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to change. The only reason we can no longer see the salt is that, once ____________, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

13. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, grinding, and tearing are examples of physical changes. All changes of state are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new substances. Dissolving is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to change. The only reason we can no longer see the salt is that, once dissolved, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always _____________. That means that it is possible to go back to the starting substance.

14. Physical Changes In a physical change, the appearance of a substance may change, but the bonds holding the atoms together in molecules and ions have not been broken and new bonds have been made. Physical changes are also accompanied by energy changes. Ripping, cutting, grinding, and tearing are examples of physical changes. All changes of state are physical changes. Although melting, freezing, boiling, and condensing will change the appearance of a substance, they do not produce new substances. Dissolving is usually considered to be a physical change as well. For example, when salt dissolves in water, the salt seems to disappear. However, this does not cause the individual sodium and chloride ions or water molecules to change. The only reason we can no longer see the salt is that, once dissolved, the ions are slightly separated from each other. This makes them to small to see. Physical changes are always reversible. That means that it is possible to go back to the starting substance. http://www.youtube.com/watch?v=_2NvwlnKVtU

15. Evidence of Chemical Changes • A chemical change produces new ____________ with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new ________ are formed while other _______ are broken. • You start with the substances that are going to react. These substances are called ____________. The new substances produced are called ___________. • Evidence that a chemical change has occurred includes:

16. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new ________ are formed while other _______ are broken. • You start with the substances that are going to react. These substances are called ____________. The new substances produced are called ___________. • Evidence that a chemical change has occurred includes:

17. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called ____________. The new substances produced are called ___________. • Evidence that a chemical change has occurred includes:

18. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called reactants. The new substances produced are called ___________. • Evidence that a chemical change has occurred includes:

19. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called reactants. The new substances produced are called products. • Evidence that a chemical change has occurred includes:

20. Evidence of Chemical Changes

21. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called reactants. The new substances produced are called products. • Evidence that a chemical change has occurred includes:

22. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called reactants. The new substances produced are called products. • Evidence that a chemical change has occurred includes: • Colour change http://www.youtube.com/watch?v=YFOFlQOJO3g

23. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called reactants. The new substances produced are called products. • Evidence that a chemical change has occurred includes: • Colour change • Heat, light, sound produced (or consumed) http://www.youtube.com/watch?v=QJ3n7wUA764

24. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called reactants. The new substances produced are called products. • Evidence that a chemical change has occurred includes: • Colour change • Heat, light, sound produced (or consumed) • Bubbles of gas form http://www.youtube.com/watch?v=gihAT6eXaoc

25. Evidence of Chemical Changes • A chemical change produces new substances with new properties and is always accompanied by energy changes, which might or might not be noticeable. In a chemical change, new bonds are formed while other bonds are broken. • You start with the substances that are going to react. These substances are called reactants. The new substances produced are called products. • Evidence that a chemical change has occurred includes: • Colour change • Heat, light, sound produced (or consumed) • Bubbles of gas form • A precipitate may form (solid in a liquid) http://www.youtube.com/watch?v=8RmVwz2fNGc

26. Chemical and Physical Changes and Energy Both chemical and physical changes are accompanied by ________ changes. In an explosion, the driving force is the rapid release of energy. This kind of a process is described as ____________ (“exo” means leaving). An exothermic reaction involves the overall release of energy in the form of ______ and _______. An _____________ (“endo” means entering) reaction involves the overall absorption of energy by the system.

27. Chemical and Physical Changes and Energy Both chemical and physical changes are accompanied by energy changes. In an explosion, the driving force is the rapid release of energy. This kind of a process is described as ____________ (“exo” means leaving). An exothermic reaction involves the overall release of energy in the form of ______ and _______. An _____________ (“endo” means entering) reaction involves the overall absorption of energy by the system.

28. Chemical and Physical Changes and Energy Both chemical and physical changes are accompanied by energy changes. In an explosion, the driving force is the rapid release of energy. This kind of a process is described as exothermic (“exo” means leaving). An exothermic reaction involves the overall release of energy in the form of ______ and _______. An _____________ (“endo” means entering) reaction involves the overall absorption of energy by the system.

29. Chemical and Physical Changes and Energy Both chemical and physical changes are accompanied by energy changes. In an explosion, the driving force is the rapid release of energy. This kind of a process is described as exothermic (“exo” means leaving). An exothermic reaction involves the overall release of energy in the form of heat and light. An _____________ (“endo” means entering) reaction involves the overall absorption of energy by the system.

30. Chemical and Physical Changes and Energy Both chemical and physical changes are accompanied by energy changes. In an explosion, the driving force is the rapid release of energy. This kind of a process is described as exothermic (“exo” means leaving). An exothermic reaction involves the overall release of energy in the form of heat and light. An endothermic (“endo” means entering) reaction involves the overall absorption of energy by the system. http://www.youtube.com/watch?v=HjR0mWdIsJ0 http://www.youtube.com/watch?v=yTzcoyzPQE0