Terms Chapter 2 Flashcards
Atomic Mass
Number of protons and neutrons in an atom
Atomic Number
Number of protons in an atom
Atom*
Smallest particle of an element
Chemical Change
A process by which a substance is changed into a different substance by changing its chemical composition
Chemical Energy
Energy produced or absorbed in a chemical reaction
Combustion
Burning to produce heat or work
Conservation of Matter*
the principle that during an ordinary chemical change, there is no detectable increase or decrease in the quantity of matter; i.e., mass cannot be created or destroyed.
Electricity
a fundamental form of energy, consisting of oppositely charged electrons and protons that produce light, heat, magnetic force, and chemical changes
Electromagnetic Radiation
Different frequencies of radiation (UV, infrared, gamma, etc.)
Electron
a stable subatomic particle with a charge of negative electricity found in atoms.
Element
substance that cannot be broken down further by chemical means.
Energy*
anything that has the ability to do work
Entropy*
a measure of the disorder or randomness of a closed system; more entropy means less energy is available for doing work. The total entropy of an isolated system cannot decrease when the system undergoes a change; it can remain constant for reversible processes, and will increase for irreversible ones.
First Law of Thermodynamics*
the total energy of an isolated system remains constant
Nuclear Fission*
the division of a nucleus into two or more parts with masses of equal order of magnitude
Fuel
any material that involves energy in a nuclear reaction.
Nuclear Fusion*
a reaction between two light nuclei resulting in the production of a nuclear species heavier
Half-life
the length of time during which, on the average, half of a large number of radioactive nuclides decay
Heat
amount of energy travelled from one body to another based on temperature differences
Heat of fusion
the heat absorbed by a unit mass of a solid at its melting point in order to convert the solid into a liquid at the same temperature.
Heat of vaporization
the heat required per unit mass to change a substance from a liquid to a vapor at its boiling point.
Isotope
a radioactive form of an element
Kinetic Energy
amount of work that an object can do as a result of motion
Mechanical Energy
sum of kinetic and potential energy of an object
Molecule
the smallest chemical species of a substance that is capable of stable independent existence.
Neutron
particle with the same mass as proton but no electric charge
Nonspontaneous process
process that requires energy to continue the process
Nuclear energy
energy released through a nuclear reaction (fusion or fission)
Nucleus
dense region at center of atom; composed of protons and neutrons
Nutrients
chemicals that are needed by living organisms
Physical Change
change in matter that rearranges molecules but does not affect their internal structures
Potential Energy
stored energy in a system based on its still state (inverse of kinetic energy)
Power
rate at which work is done
Power Plant (will not need to know this)
a general term for any facility in which some other form of energy (e.g., steam, hydropower) is converted into electrical energy.
Propane
a colorless, straight-chain hydrocarbon gas with with formula C3H8 that boils at a temperature of -43.67 degrees Fahrenheit
Proton
particle with a positive electric charge
Radioactivity
the spontaneous breakdown of an atomic nucleus with the emission of particles and rays
Radiocarbon dating (will not need to know this)
a precise method of dating ancient organic artifacts, an important tool in modern archaeology and other branches of science
Radioisotope
radioactive isotope
Second Law of Thermodynamics*
heat will not flow spontaneously from a cold object to a hot one
Spontaneous Process
a process that occurs because of internal properties, with no external forces required to continue the process, although external forces may be required to initiate it
Trace Element
any chemical Element that an organism needs very small quantities of to survive
