Chapter 2 Flashcards
Model
Approximate representation of simulation of a system
Scientific theory
Well-tested and widely accepted scientific hypothesis or a group of related hypothesis
Scientific law or law of nature
Well-tested and widely accepted description of what we find happening repeatedly in nature in the same way
Tentative science or frontier science
Not yet widely accepted or tested by peer review
Reliable source
Consists of data, hypothesis, models, theories, and laws that are widely accepted
Unreliable science
Results presented as being reliable without having undergone the rigors of widespread peer review
Matter
Anything that has mass and takes up space
Element
A fundamental type of matter that has a unique set of properties and cannot be broken down into simpler substances by chemical means
Compounds
Combination of two or more different elements held together in fixed proportions
Atomic theory
Idea that all elements are made up of atoms
Atomic number
Number of protons in nucleus
Mass number
Total number of neutrons and protons in its nucleus
Isotopes
An element having the same atomic number but different mass numbers
Molecule
A combination of two or more atoms of the same or different elements held together by forces called chemical bonds
Ion
An atom or a group of atoms with one or more net positive or negative electrical charges
Acidity
A chemical characteristic that helps determine how a substance dissolved in water will interact with and affect its environment
Ph
A measure of acidity; measure of hydroxide and hydrogen ions
Organic compounds
Chemicals that contain two or more carbon atoms combined with atoms of one or more other elements
Inorganic compounds
Anything that is not an organic compound is inorganic
Cells
Fundamental structural and functional units of life
Genes
Within some DNA molecules there are certain sequences of nucleotides called
Trait
Coded genetic information leads to this
Chromosome
Thousands of genes make up a single chromosome
Nuclear change
Change in nuclei of its atoms
Heat
The total kinetic energy of all moving atoms, ions, or molecules within a given substance
Electromagnetic radiation
Energy travels in the form of wave as a result of changes in electrical and magnetic fields
Energy quality
A measure of the capacity of a type of energy to do useful work
High-quality energy
A great capacity to do useful work because it is concentrated
Low quality energy
Is so dispersed that it has little capacity to do useful work
First law of thermodynamics or law of conservation of energy
Whenever energy is converted from one form to another in a physical of chemical change, no energy is created or destroyed
Second law of thermodynamics
Whenever energy is converted from one form to another, a lower quality energy is created
System
A set of components that function and interact in some regular way
Most systems have the following key components
Inputs from the environment, flows or throughputs of matter and energy within the system, and outputs to the environment
Feedback
Systems are affected by this. It is any process that increases or decreases a change to a system
Feed-back loop
Causes a system to change further in the same direction
Negative or corrective feedback loop
Causes a system to change in the opposite direction from which it is moving
Time delay
A lack of response during a period of time between the input of a feedback stimulus and the system’s response to it
Tipping point
The point at which a fundamental shift in the behavior of a system occurs
Synergistic interaction
When two or more processes interact so that the combined effect is greater than the sum of their separate effects
Science
A human effort to discover how the physical world works by making observations and measurements, and carrying out experiments.
