Chemical Reactions (Notes)

• The following slides contain the notes for Chemical Reactions.

• Make sure to copy the notes in your Notes section of your binder/notebook.

Evidence for Chemical Reactions

Chemical reactions involve two main types of changes that can be observed:

• Formation of new substances

• Changes in energy
  

Evidence for Chemical Reactions

Evidence of Reactions:

• Changes in Temperature

• Light Production

• Precipitate Formation

• Gas Formation

• Color Change

Evidence for Chemical Reactions

Changes in Energy:

• As matter changes, it can either absorb or release energy

• The change in energy can be indicated by a change in temperature.

Evidence for Chemical Reactions

Changes in Energy:

• Endothermic

  • energy is absorbed

  • Usually a decrease in temperature

• Exothermic

  • energy is released

  • Usually an increase in temperature

Properties and Changes In Matter

Matter can be described in terms of two kinds of properties:

• Physical

• Chemical

Properties and Changes In Matter

Physical Properties:

• Color

• Texture

• Hardness

• Shine

• Flexibility

Properties and Changes In Matter

Chemical Properties:

• Burning

• Rusting

• Tarnishing

Properties and Changes In Matter

Physical Changes:

• Bending

• Breaking

• Crushing

• Cutting

Properties and Changes In Matter

Chemical Changes:

• When a substance changes into a completely new, different substance or compound.

• Chemical changes occur when bonds break and new bonds form.