Chapter 2.3: Chemical Transformations Involve Energy and Energy Transfers

Flashcards from Chapter 2.3 of Principles of Life, 3rd Edition.

Molecular stability

This is inversely associated with the molecule’s level of energy; higher-energy states transition to lower-energy states for greater levels of this

Energy

The capacity to produce a change, as all changes in the universe require this in a transformation

Kinetic energy

The energy of movement, including thermal, sound, and electromagnetic energy

Potential energy

Stored energy, including gravitational, elastic, chemical-bond, and nuclear energy

First Law of Thermodynamics

States that energy cannot be created or destroyed, only converted or moved before and after transformation

Second Law of Thermodynamics

States that when an energy transformation occurs, there is an increase in entropy and thus less usable energy, even though the total amount of energy stays the same

• Energy transfers that increase entropy need an input of energy to begin

• Seen in food chains, as the total amount of available caloric energy decreases at every step

Bond strength

Determined by how much energy is needed to break it, with higher potential energy states being easier to break for greater stability

• Converting energy from this high to low state results in the release of chemical-bond energy

Entropy

A measure of disorder or how spread out energy is, thus making it unusable