Exam #1 Env Bio
Experimental Group
chosen variable is changed in a known way
Control Group
chosen variable is not changed
What do scientists do?
collect data and develop theories, models, and laws about how nature works
Science
an attempt to gain knowledge on how nature works, use knowledge to predict what is likely to happen
Scientific Process
1) Observe behavior
2) Attempt to identify cause and effect
3) Make predictions
4) Test predictions
5) Draw conclusions
Scientific Hypothesis
possible and testable explanation of what they observe in nature or in the results of their experiment (may or may not be correct)
Model
approximate representation or simulation of a sustem being studied
Scientific Theory
scientific hypothesis that has been well-tested and widely accepted
never been proven false
Scientific Laws
well tested and widely accepted description of what we find happening over and over in the same way in nature
4 Important Feature of Scientific Process:
-Curiosity
-Skepticism
-Peer Review
-Reproducibility
Fundmental Part of Science
Testing
3 Scientific Limitations
-scientists cannot prove or disprove anything absolutely
-have bias about results
-huge number of interacting variables and complex interactions
Natural Greenhouse Effect
keeps atmosphere temp moderate
-How much warming over last 50 years?
-How much caused by adding carbon dioxide to atmosphere?
-How much will atmosphere warm in future, and effects?
Matter
-consists of elements and compounds which are in turn made up of atoms, ions, and molecules
-when it undergoes physical/chemical change, no atoms are created or destroyed (conservation of matter)
Matter
anything that has mass and occupies space
-3 physical states: solid, liquid, gas
-2 chemical form: elements and compounds
Element
fundamental substances with unique set of properties
Compound
combinations of two or more different elements held together in fixed proportions
-organic: carbon based
-inorganic: everything else
Atoms
most basic building block of matter
-smallest unit of matter into which an element can be divided and still have the same chemical properties
-subatomic particles: protons, neutrons, electrons
Atomic Theory
all elements are made from atoms
Nucleus
small dense center of an atom
Atomic Number
number of protons in the nucleus of its atom
Mass number
total number of neutrons and protons in its nucleus
Isotopes
element with same atomic number but different mass numbers
Ion
an atom with one or more net positive or negative electrical charges
-2nd building block
-made up of protons neutrons, and electrons
Molecule
combination of two or more atom of the same or different chemical elements
-3rd building block
Chemical Formula
shows number of each type of atom or ion in a compound
Complex Organic Compounds
essential to life
-composed of macromolecules
Polymers
formed when a number of simple organic molecules (monomers) are linked together by chemical bonds
-complex carbs
-proteins
-nucleic acid
Cells
smallest and most fundmental structural and functional units of life
-DNA
Cell Theory
all things living are composed of cells
Genes
certain sequences of nucleotides within DNA
Chromosomes
special DNA molecule together with a number of proteins
-1000s of genes
Matter Quality
measure of how useful a given sample of matter is as a resource for humans
Matter goes through 3 types of nuclear change
-radioactive decay
-nuclear fusion
-nuclear fission
Radioactive Decay
nuclei of unstable isotopes spontaneously emit fasat-moving chunks of matter (alpha / beta)
or emit high energy radiation (gamma rays)
Nuclear Fission
nuclei of certain isotopes with large mass numbers are split apart into light nuclei when struck by a neutron
Nuclear Fusion
two isotopes of light elements are forced together at extremely high temps until they fuse to form a heavier nucleus
Energy
the capacity to do work or transfer heat
potential: stored energy
kinetic: moving energy
Thermodynamics
study of energy transformation
-law of conservation of energy
-energy can be converted
-neither created or destroyed
3 Big Ideas
1) There is no away
2) You cannot get something from nothing
3) You cannot break even
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