The Nature of Energy (6.1.1) Flashcards
• Kinetic energy (KE) is energy of motion; potential energy (PE) is stored energy; internal energy (E) is kinetic energy plus potential energy.
• Kinetic energy (KE) is energy of motion; potential energy (PE) is stored energy; internal energy (E) is kinetic energy plus potential energy.
• Thermochemistry is the study of energy changes for a chemical system.
• Thermochemistry is the study of energy changes for a chemical system.
Energy is the capacity to do work or transfer heat.
Kinetic energy (KE) is the energy associated with
particles in motion.
Potential energy (PE) is stored energy, or the
energy inherent in a system at a particular state.
The system is the portion of the universe under
study. The surroundings are the rest of the
universe.
Internal energy (E) is the sum of the kinetic energy
and the potential energy of a system.
Thermochemistry is the study of energy changes for
a chemical system. For example, the breaking of
bonds and the excitation of electrons involve
changes in energy.
The change in internal energy for a system is
denoted ∆E. The change in internal energy is equal
to the final energy (Ef) minus the initial energy (Ei).
Work (w) and heat (q) are two general ways for a
system to exchange energy with the surroundings.
Work is measured in joules (J). Examples of work
include lifting (w = F • d, where F is the
gravitational force) and separating socks
(w = F • d, where F is the Coulomb force).
Heat is measured in calories (cal). A calorie is the
amount of heat required to heat 1 g of water from
14.5˚C to 15.5˚C. 1 cal = 4.184 J.
Work can be converted to heat. For example, if you
beat a metal pole with a hammer, the pole becomes
warm.
Energy is the capacity to do work or transfer heat.
Kinetic energy (KE) is the energy associated with
particles in motion.
Potential energy (PE) is stored energy, or the
energy inherent in a system at a particular state.
The system is the portion of the universe under
study. The surroundings are the rest of the
universe.
Internal energy (E) is the sum of the kinetic energy
and the potential energy of a system.
Thermochemistry is the study of energy changes for
a chemical system. For example, the breaking of
bonds and the excitation of electrons involve
changes in energy.
The change in internal energy for a system is
denoted ∆E. The change in internal energy is equal
to the final energy (Ef) minus the initial energy (Ei).
Work (w) and heat (q) are two general ways for a
system to exchange energy with the surroundings.
Work is measured in joules (J). Examples of work
include lifting (w = F • d, where F is the
gravitational force) and separating socks
(w = F • d, where F is the Coulomb force).
Heat is measured in calories (cal). A calorie is the
amount of heat required to heat 1 g of water from
14.5˚C to 15.5˚C. 1 cal = 4.184 J.
Work can be converted to heat. For example, if you
beat a metal pole with a hammer, the pole becomes
warm.
