a substance that cannot be broken down into a simpler substance by ordinary chemical changes. Consists of atoms of only one type
/Chemistry Term
2 / proton / a positively charged particle located in an atom's nucleus / Chemistry Term3 / neutron / a neutral particle located in an atom's nucleus / Chemistry Term
4 / nucleus / the central region of an atom where most of the atom's mass is found in protons and neutrons / Chemistry Term
5 / electron / a negatively charged particle located outside an atom's nucleusabout 2000 times smaller than either a proton or neutron / Chemistry Term
6 / atomic number / the total number of protons in an atom's nucleus / Chemistry Term
7 / atomic mass # / the total number of protons and neutrons in an atom's nucleus / Chemistry Term
8 / ion / an atom or group of atoms that has a positive or negative electric charge; forms by atoms gaining or losing electrons / Chemistry Term
9 / periodic table / a table of the elements, arranged by atomic number, that shows the patterns in their properties / Chemistry Term
10 / group / a vertical column in the periodic table of the elements that have similar properties / Chemistry Term
11 / period / a horizontal row in the periodic table of the elements that have varying properties / Chemistry Term
12 / reactive / property in which a substance is likely to undergo a chemical change / Chemistry Term
13 / metal / an element that tends to be shiny, easily shaped, and a good conductor of electricity and heat / Chemistry Term
14 / nonmetal / an element that is not a metal and has properties generally opposite to those of a metal / Chemistry Term
15 / Metalloid / an element that has properties of both metals and nonmetals / Chemistry Term
16 / density / the ratio of the mass of a substance to the volume of the substance (mass/volume) / Hydrosphere Term
17 / specific heat / amount of heat energy required to raise the temperature of 1 kg of a substance by 1 degree Celsius / Hydrosphere Term
18 / divide / a ridge, or continuous line of high land, from which water flows in different / Hydrosphere Term
19 / turnover / the yearly rising and sinking of cold and warm water layers in a lake / Hydrosphere Term
20 / eutrophication / an increase in nutrients in a lake or pond, occurring naturally or as a result of pollution, which causes increased growth of algae and plants decreasing the amount of oxygen in the water / Hydrosphere Term
21 / aquifer / an underground layer of permeable rock that contains water / Hydrosphere Term
22 / point-source pollution / pollution that enters water from a specific source that can be identified / Hydrosphere Term
23 / nonpoint-source pollution / pollution with a widely spread source that can't be tied to a specific point of origin / Hydrosphere Term
24 / desalination / the process of removing salt from ocean water / Hydrosphere Term
25 / continental shelf / the flat or gently sloping land that lies submerged around the edges of a continent and that extends from the shoreline out to the continental slope / Hydrosphere Term
26 / sonar / a system that uses underwater sound waves to measure distance and locate objects / Hydrosphere Term
27 / downwelling / the movement of water from the surface to greater depths carrying oxygen down allowing animals to live in the deep ocean / Hydrosphere Term
28 / upwelling / the vertical movement of deep water up to the surface
bringing up nutrients from the deep ocean allowing animals to thrive / Hydrosphere Term
29 / estuary / a shoreline area where fresh water from a river mixes with salt water from the ocean / Hydrosphere Term
30 / turbidity / a measure of the clarity of water that depends on the amount, size and composition of suspended matter such as clay, silt, phytoplankton and other microscopic organisms / Hydrosphere Term
31 / hydrothermal vent / an opening in the sea floor from which heated water rises and mixes with the ocean water above / Hydrosphere Term
32 / compound / a substance made up of two or more different types of atoms bonded together / Chemistry Term
33 / chemical formula / an expression that shows the number and types of atoms joined in a compound / Chemistry Term
34 / molecule / a group of atoms that are held together by covalent bonds so that they move / Chemistry Term
35 / chemical reaction / the process by which chemical changes occur and new substances are formed; atoms are rearranged - chemical bonds are broken and formed / Chemistry Term
36 / reactant / a substance that is present at the beginning of a chemical reaction, takes part in the chemical reaction, and is changed into a new substance / Chemistry Term
37 / product / a substance formed by a chemical reaction; made by the rearrangement of atoms and bonds in reactants / Chemistry Term
38 / Precipitate / a solid substance that forms as a result of a chemical reaction between chemicals in two liquids / Chemistry Term
39 / Catalyst / a substance that increases the rate of a chemical reaction but is not consumed in the reaction / Chemistry Term
40 / Law of Conservation
of Mass / a scientific law stating that during a chemical reaction, matter is not created nor destroyed. / Chemistry Term
41 / coefficient / the number before a chemical formula that indicates how many molecules are involved in a chemical reaction / Chemistry Term
42 / semiconductor / a material that can precisely control the conduction of electrical signals / Chemistry Term
43 / solution / a mixture of two or more substances that is the same throughout / Chemistry Term
44 / solute / in a solution, a substance that is dissolved in a solvent / Chemistry Term
45 / solvent / in a solution, the substance that dissolves a solute / Chemistry Term
46 / concentration / the amount of solute that is dissolved in a solvent at a particular temperature / Chemistry Term
47 / dilute / a solution having a low concentration of solute / Chemistry Term
48 /
saturated / a solution containing the maximum amount of a solute that can be dissolved in a solvent at a given temperature / Chemistry Term
49 /
solubility / the amount of a solute that dissolves in a certain amount of a solvent at a given temperature to produce a saturated solution / Chemistry Term
50 / acid / a substance that can donate a proton to another substance that has a ph below 7 / Chemistry Term
51 / base / a substance that can accept a proton from another substance that has a ph above 7 / Chemistry Term
52 / pH / the concentration of hydrogen ions in a solution measurement of acidity / Chemistry Term
53 / neutral / describing a solution that is neither an acid nor a base substance that has a pH of 7 / Chemistry Term
54 / Parasites / An organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense. / Microbiology Term
55 / cell membrane / the outer boundary of the cytoplasm; a layer that controls what enters or leaves a cell; a protective covering enclosing an entire cell / Micro/Cell Biology Term
56 / cytoplasm / a thick, gelatin-like material contained within the cell membrane where most of the work of the cell is carried out / Micro/Cell Biology Term
57 / eukaryotic cell / a cell in which the genetic material is enclosed within a nucleus, surrounded by its own membrane / Micro/Cell Biology Term
58 / nucleus / the structure in a eukaryotic cell that contains the genetic material a cell needs to reproduce and function / Micro/Cell Biology Term
59 / organelle / a structure in a cell that is enclosed by a membrane and that performs a particular function / Micro/Cell Biology Term
60 / prokaryotic cell / a cell that lacks a nucleus and other organelles / Micro/Cell Biology Term
61 / mitochondria / organelles that release energy by using oxygen to break down sugars / Micro/Cell Biology Term
62 / chemical energy / the energy stored in the bonds between atoms of every molecule / Chemistry Term
63 / cellular respiration / a process in which cells use oxygen to release energy stored in sugars such as glucose / Micro/Cell Biology Term
64 / Diffusion / the process by which molecules spread out, or move from an area of higher concentration to an area of lower concentration / Micro/Cell Biology Term
65 / osmosis / the diffusion of water through a membrane from an area of high concentration to an area of lower concentration / Micro/Cell Biology Term
66 / mitosis / the phase in the cell cycle during which the nucleus divides / Micro/Cell Biology Term
67 / asexual reproduction / the process by which a single organism produces offspring that have the same genetic material / Micro/Cell Biology Term
68 / microorganism / a very small organism that can be seen only with a microscope EXAMPLE: bacteria / Micro/Cell Biology Term
69 / bacteria / a large group of one-celled organisms that sometimes cause disease / Micro/Cell Biology Term
70 / Virus / a nonliving, disease-causing particle that uses the materials inside cells to reproduce; consists of genetic material enclosed in a protein coat / Micro/Cell Biology Term
71 / pathogen / agents that cause disease / Micro/Cell Biology Term
72 / antibiotic / a substance that can destroy bacteria / Micro/Cell Biology Term
73 / infectious disease / diseases that can be spread; caused by viruses, bacteria and other pathogens / Micro/Cell Biology Term
74 / vector / insects or animals that spread diseases to humans / Micro/Cell Biology Term
75 / carrier / people who are infected with a disease and can infect others but do not show symptoms of the disease themselves / Micro/Cell Biology Term
76 / noninfectious disease / diseases that cannot be spread by pathogens / Micro/Cell Biology Term
77 / resistance / the ability of an organism to protect itself from a disease or the effects of a substance / Micro/Cell Biology Term
78 / Producer / an organism that captures energy from sunlight and transforms it into chemical energy that is stored in energy-rich carbon compounds; a source of food for other organisms / Micro/Cell Biology Term
79 / decomposer / an organism that feeds on and breaks down dead plant or animal matter / Micro/Cell Biology Term
80 / Metalloid / An element that has both properties of metals and nonmetals. / Chemistry Term
81 / host cell / a cell that a virus infects and uses to make copies of itself / Micro/Cell Biology Term
82 / plankton / mostly microscopic organisms that drift in great numbers through bodies of water / Micro/Cell Biology Term
83 / protozoa / animal-like protists that eat other organisms or decaying parts of other organisms / Micro/Cell Biology Term
84 / geologic time scale / chart organized by scientists that divides Earth's history into intervals of time defined by major events or changes on Earth / Earth History Term
85 / index fossil /
- fossils of species that existed on Earth only during specific periods of time
- were abundant and widespread geographically
86 / Law of Superposition / scientific law that states in undisturbed sedimentary rock layers, the oldest rock layers are on the bottom and the youngest rock layers are on the top / Earth History Term
87 / unconformity / a gap in the sedimentary rock record that is due to erosion wearing away rock layers or periods of time without deposition of rock layers / Earth History Term
88 / plate tectonics /
- Earth's lithosphere is made up of huge plates that move over the Earth's surface
89 / continental drift / a hypothesis proposed by Alfred Wegener, a German scientist, stating that Earth's continents were once joined in a single landmass called Pangaea and gradually drifted apart / Earth History Term
90 / mid-ocean ridge /
- a long line of sea-floor mountains where new ocean crust is formed by volcanic activity along a divergent boundary
- forms the longest chain of mountains on Earth
- Earth History Term
91 / topographic map /
- type of map that uses contour lines to represent the shape and elevation of the land
- Earth History Term
92 / urban sprawl / the spreading of a city and its suburbs over rural land / Earth History Term
93 / permeable /
- Allows substances to easily pass through
- Hydrosphere Term
94 / impermeable / Does not allow substances to pass through / Hydrosphere Term
95 / Subscript / The number written slightly below and to the right of a chemical symbol that shows how many atoms of an element are in a compound / Chemistry Term
96 / Natural selection / The theory that explains how populations can eventually evolve into new species / Earth History Term
97 / Relative age / The age of an object or event in comparison to another object or event / Earth History Term
98 / Water table / The highest part in the ground that is saturated, or completely filled with water / Hydrosphere term
99 / Variable / Any factor that can change in a controlled experiment / Chemistry Term
100 / Control group / A standard set up in which to the experimental results are compared / Chemistry Term
101 / Heterogeneous Mixture / A substance that is not uniform throughout. / Chemistry Term
102 / Homogeneous Mixture / A substance that is evenly spread throughout. Particles not distinguishable. / Chemistry Term
103 / Fossil Fuel / A natural fuel such as coal or gas, formed in the geological past from the remains of living organisms.
/ Energy Term
104 / Nonrenewable / Used to describe energy sources that exist in a limited amount on Earth. Thus all available material could eventually be completely used. / Energy Term
105 / Renewable / Energy which comes from natural resources, which naturally replenish. / Energy Term
106 / Watersheds / Areas of land that water drains in to when the ground is saturated or impermeable. / Hydrosphere Term
107 / River Basin / The entire geographical area drained by a river and its tributaries. / Hydrosphere Term
108 / Salinity / The amount of salt in a substance. / Hydrosphere Term
109 / Deep Ocean Technology / Technology that continuously provides information about new life forms, Earth resources, and geologic processes. / Hydrosphere Term
110 / Nitrates / A form of nutrient pollution. / Hydrosphere Term
111 / Clean Water Act / Passed in the US in 1972, this law focused regulation on industrial waste and water contamination as well as waste water treatment. / Hydrosphere Term
112 / Fungi / Any of a group of unicellular, or multicellular, spore-producing organisms feeding on organic matter. / Microbiology Term
113 / Biotechnology / Technology that uses living processes to make advancements in the areas of health, medicine and industry. / Microbiology Term
114 / Ecosystem / A biological environment consisting of all the organisms living in a particular area, as well as all the nonliving resources. / Hydrosphere Term
115 / Populations / A group of organisms of the same species inhabiting a given area. / Hydrosphere Term
116 / Food Chain / The sequence of who eats whom in a biological community. / Hydrosphere Term
117 / Absolute Age / The age of a rock as determined by the measurement of radioactive decay from the time of the rock's formation. / Earth History Term
118 / Evolution / Adaptations that arise through natural selection by genetic variation / Earth History Term
119 / Adaptations / Special features that allow a plant or animal to live in a particular place or habitat. / Earth History Term