Transcript Introduction to Energy and Spontaneity-- Powerpoint presented Mon 09/28

Intro to Periodic Trends
About Energy, Stability and Spontaneity
BLANK
Positive Energy Values
• “+” energy values denote that energy must be
___________ the system in order to perform
the process described.
• These processes are called _______________.
• For example: being pushed up stairs,
electrons being excited in atom
Negative Energy Values
• “-” energy values denote that energy is
_____________ the system as the process
described takes place.
• These processes are called _______________.
• For example: Falling down stairs,
electrons returning to ground state
Energy and Stability
• A process in which energy is absorbed
(+ energy) results in matter which is ________
stable than the starting matter.
• For example: being pushed up stairs
OR 2 north poles of magnets aimed at each
other
Energy and Stability
• A process in which energy is released
(- energy) results in matter which is ________
stable than the starting matter.
• For example: falling down stairs
OR north and south poles of magnets aimed
at each other
Spontaneity
• A process that requires energy is a
______________ process.
i.e. Does not occur readily
• A process that releases energy is a
____________ process.
i.e. occurs readily
Overview
• Positive Energy
–
–
–
–
Endothermic
Energy Absorbed
Less Stable Particle
Non-spontaneous Process
• Negative Energy
–
–
–
–
Exothermic
Energy Released
More Stable Particle
Spontaneous Process