Exploring Physical and Chemical Changes

The video tutorial discusses chemical and physical changes, focusing on the macroscopic characteristics and bond interactions. Chemical changes involve the formation or breaking of bonds, represented by particle diagrams and chemical equations. Physical changes, such as phase changes, do not involve bond changes and can also be represented by diagrams and equations. The dissolution of salt is explored as a complex case that can be seen as both a chemical and physical change. The tutorial concludes by summarizing the classification of processes based on bond interactions and intermolecular changes.

What type of changes involve the formation or breaking of chemical bonds?

• None of the above

• Both physical and chemical changes

• Chemical changes

• Physical changes

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Which law is obeyed when bonds are rearranged in chemical changes?

• Law of conservation of energy

• Law of conservation of mass

• Law of multiple proportions

• Law of definite proportions

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NGSS.MS-PS1-5

What happens to methane and oxygen in the provided chemical equation?

• They undergo a phase change

• They dissolve

• They react to form new substances

• They remain unchanged

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NGSS.MS-PS1-2

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In physical changes, are new bonds formed?

• Only in sublimation

• Sometimes

• No, never

• Yes, always

What is sublimation?

• Solid changing to liquid

• Liquid changing to gas

• Solid changing to gas

• Gas changing to solid

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What does a particle diagram represent in the context of physical changes?

• Formation of new substances

• Mixing of substances without bond formation

• Energy changes in the substances

• Breaking of existing bonds

Which equation represents the melting of ice?

• H2O(gas) to H2O(liquid)

• H2O(solid) to H2O(liquid)

• H2O(liquid) to H2O(gas)

• CO2(solid) to CO2(gas)

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NGSS.MS-PS1-4

Is the dissolution of salt considered a chemical change, physical change, or both?

• Chemical change

• Neither

• Physical change

• Both

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NGSS.MS-PS1-2

What interactions are formed when a salt dissolves?

• Dispersion forces

• Ion-dipole interactions

• Metallic bonds

• Covalent bonds

Which process is typically classified as a physical process?

• Changes in intermolecular interactions

• Formation of chemical bonds

• Breaking of chemical bonds

• Both formation and breaking of bonds