Chapter 2 Flashcards
Atom
Minute unit made of subatomic particles that is the basic building block of all chemical elements and thus all matter. The smallest unit of an element that can exist and still have the unique characteristics of that element.
Atomic number
Number of protons in the nucleus of an atom
Atomic theory
Idea that all elements are made up of Atoms, the most widely accepted scientific theory in chemistry
Cells
Smallest living unit of an organism. Each cell is encased in an outer membrane or wall and contains genetic material (DNA) and other parts to perform its life function. Organisms such as bacteria consist of only one cell, but most organisms contain many cells.
Chemical change/ chemical reaction
Interaction between chemicals in which the chemical composition of the elements or compounds involved changes
Chemical formula
Shorthand way to show the number of atoms in the basic structural unit of a compound. Examples include H2O
Chromosome
A grouping of genes and associated proteins in plant and animal cells that carry certain types of genetic information.
Compounds
Combination of atoms, or oppositely charged ions, of two or more elements held together by attractive forces called chemical bonds. Examples NaCl
Data
Factual information collected by scientists.
Electromagnetic radiation
Forms of Kinetic energy traveling as electromagnetic waves. Examples include radio waves, TV waves, microwaves, and infrared radiation.
Electrons
Tiny particle moving around outside the nucleus of an atom. each electron has one unit of negative charge and almost no Mass.
Elements
Chemical such as hydrogen, iron, sodium, carbon, nitrogen, or oxygen, who’s distinctly different atoms serve as the basic building blocks of all matter. Two or more elements combine to form the compounds that make up most of the world’s matter.
Energy
Capacity to do work by performing mechanical, physical, chemical, or electrical task or to cause a heat transfer between two objects at different temperatures.
Energy quality
Ability of a form of energy to do useful work. High-temperature heat and the chemical energy in fossil fuels and nuclear fuels are concentrated high-quality energy. Low quality energy such as low temperature heat is dispersed or diluted and cannot do much useful work.
Feedback
Any process that increases (positive feedback) or decreases (negative feedback) a change to a system.
Feedback loop
Occurs when an output of matter, energy, or information is fed back into the system as an input and leads to changes in that system.
first law of thermodynamics/
law of conservation of energy
Whenever energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed, but energy can be changed from one form to another; you cannot get more energy out of something then you put in; in terms of energy quantity, you cannot get something for nothing. This law does not apply to nuclear changes, in which large amounts of energy can be produced from small amounts of matter
flows/throughputs
Rate of flow of matter, energy, or information through a system.
fossil fuels
Products of partial or complete decomposition of plants and animals; occurs as crude oil, coal, natural gas, or heavy oils as a result of exposure to heat and pressure and the earth’s crust over millions of years
frontier science/tentative science
Preliminary scientific data, hypotheses, and models that have not been widely tested and accepted.
genes
Coded units of information about specific traits that are passed from parents to offspring during reproduction. They consist of segments of DNA molecules found in chromosomes.
heat
Total kinetic energy of all randomly moving atoms, ions, or molecules within a given substance, excluding the overall motion of the whole object. Heat always flows spontaneously from a warmer sample of matter to a quarter sample of matter. This is one way to state the second law of thermodynamics.
high-quality energy
Energy that is concentrated and has great ability to perform useful work. Examples include high-temperature heat and the energy in electricity, coal, and oil.
inorganic compounds
All compounds not classified as organic compounds, meaning it does not have carbon.
inputs
Matter, energy, or information entering the system
ion
atom or group of atoms with one or more positive or negative electrical charges.
isotopes
Two or more forms of a chemical element that have the same number of protons but different mass numbers because they have different numbers of neutrons in their nuclei.
kinetic energy
Energy that matter has because of its mass and speed, or velocity
low-quality energy
Energy that is dispersed and has little ability to do useful work. An example is low-temperature heat.
low-quality matter
Matter that is dilute or dispersed or contains a low concentration of a useful resource.
mass number
Some of the numbers of neutrons and the number of protons in the nucleus of an atom. It gives approximate mass of that atom.
matter
Anything that has mass and takes up space. On the earth, where gravity is present, we weigh objects to determine it’s mass.
matter quality
Measure of how useful a matter resource is, based on its availability and concentration.
model
Approximate representation or simulation of a system being studied.
molecule
Combination of two or more atoms of the same chemical element or different chemical elements held together by chemical bonds.
negative feedback loop
Feedback loop that causes a system to change in the opposite direction from which it is more.
neutrons
Elementary particle in the nuclei of all atoms. It has a relative mass of one and no electric charge.
nuclear change
Process in which nuclei of certain isotope spontaneously change, or are forced to change, into one or more different isotopes. The three principal types of nuclear change are natural radioactivity, nuclear fission, or nuclear fusion.
nucleus
Extremely tiny center of an atom, making up most of the atoms mass. It contains one or more positively charged protons and one or more neutrons with no electric charge
organic compounds
Compounds containing carbon atoms combine with each other and with atoms of one or more other elements such as hydrogen, oxygen, nitrogen, sulfur, phosphorus, chlorine, and flourine.
peer review
Process of scientist reporting details of the methods and models they used, the results of their experiments, and the reasoning behind their hypotheses for other scientist working in the same field to examine and criticize.
pH
Numeric value that indicates the relative acidity or alkalinity of a substance on a scale of 0 to 14 with the neutral point at seven. Acid solutions have pH values lower than seven; basic or alkaline solutions have pH values greater than seven.
physical change
Process that alters one or more physical properties of an element or a compound without changing its chemical composition. Examples include changing the size and shape of a sample of matter and changing a sample of matter from one physical state to another.
positive feedback loop
Feedback loop that causes a system to change further in the same direction.
potential energy
Energy stored in object because of its position or the position of it’s parts.
protons
Positively charged particle in the nuclei of all atoms. Each proton has a relative mass of 1 and a single positive charge.
science
Attempts to discover order in nature and use that knowledge to make predictions about what is likely to happen in nature.
scientific hypothesis
An educated guess that attempts to explain a scientific law or certain scientific observations.
scientific (natural) law
Description of what scientists find happening in nature repeatedly in the same way, without known exception.
scientific theory
A well tested and widely accepted scientific hypothesis.
second law of thermodynamics
Whenever energy is converted from one form to another in a physical or chemical change, we end up with lower quality or less usable energy than we started with. In any conversion of heat energy to useful work, some of the initial energy input is always degraded to lower quality, more dispersed, less useful energy, usually low temperature heat that flows into the environment; you cannot break even in terms of energy quality
synergistic interaction/synergy
Interaction of two or more factors or processes so that the combine effect is greater than the sum of their separate effects.
system
Set of components that function and interact in some regular and theoretically predictable manner.
time delay
In a complex system, the period of time between the input of a feedback stimulus and the system’s response to it.
tipping point
Threshold level at which an environmental problem causes a fundamental and a irreversible shift in the behavior of a system.
