 | Term | Definition |
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science |
the knowledge obtained by observing natural events and conditions in order to discover facts and formulate laws or principles that can be verified or tested |
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technology |
the application of science for practical purposes |
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scientific law |
a summary of many experimental results and observations; tells how things work |
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scientific theory |
an explanation for some phenomenon that is based on observation, experimentation, and reasoning |
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critical thinking |
the ability and willingness to assess claims critically and to make judgments on the basis of objective and supported reasons |
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scientific method |
a series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions |
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variable |
a factor that changes in an experiment in order to test a hypothesis |
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length |
a measure of the straight-line distance between two points |
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mass |
a measure of the amount of matter in an object |
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volume |
a measure of the size of a body or regioin in three-dimensional space |
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weight |
a measure of the gravitational force exerted on an object |
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scientific notation |
a method of expressing a quantity as a number multiplied by 10 to the appropriate power |
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precision |
the exactness of a measurement |
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significant figure |
a prescribed decimal place that determines the amount of rounding off to be done based on the precision of the measurement |
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accuracy |
a description of how close a measurement is to the true value of the quantity measured |
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chemistry |
the scientific study of the composition, structure, and properties of matter and the changes taht matter undergoes |
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matter |
anything that has mass and takes up space |
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element |
a substance that cannot be seperated or broken down into simpler substances by chemical means |
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atom |
the samllest unit of an element that maintains the properties of that element |
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compound |
a substance made of atoms of two or more different elements that are chemically combined |
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molecule |
the smallest unit of a substance that keeps all of the physical and chemical properties of that substance |
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chemical formula |
a combination of chemical symbols and numbers to represent a substance |
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pure substance |
a sample of matter, either a single element or a single compound, that has definite chemical and physical properties |
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mixture |
a combination of two or more substances that are not chemically combined |
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melting point |
the temperature and pressure at which a solid becomes a liquid |
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boiling point |
the temperature at which a liquid becomes a gas |
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density |
the ratio of the mass of a substance to the volume of a substance |
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reactivity |
the ability of a substance to combine chemically with another substance |
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flammability |
the ability of a substance to react in the presence of oxygen and burn when exposed to a flame |
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physical change |
a change of matter from one form to another without a change in chemical properties |
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chemical change |
a change taht occurs when a substance changes composition by forming one or more new substances |
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plasma |
a state of matter that starts as a gas and then becomes ionized |
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energy |
the capacity to do work |
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thermal energy |
the kinetic energy of a substance's atoms |
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evaporation |
the change of a substance from a liquid to a gas |
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sublimation |
the process in which a solid changes directly into a gas (the term is sometimes also used for the reverse process) |
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condensation |
the change of a substance from a gas to a liquid |
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fluid |
a nonsolid state of matter in which the atoms or molecules are free to move past each other, as in a gas or liquid |
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buoyant force |
the upward force exerted on an object immersed in or floating on a fluid |
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pressure |
the amount of force exerted per unit area of a surface |
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Archimedes' principle |
the principle that states taht the buoyant force on an object in a fluid is an upward force equal to the weight of the volume of fluid that the object displaces |
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pascal |
the SI unit of pressure; equal to the force of 1 N exerted over an area of 1 m2 |
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Pascal's principle |
the principle that states that a fluid in equilibrium contained in a vessel exerts a pressure of equal intensity in all directions |
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viscosity |
the resistance of a gas or liquid to flow |
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Boyle's law |
the law taht states taht for a fixed amount of gas at a constant temperature, the volume of the gas increases as the pressure of the gas decreases and the volume of the gas decreases as the pressure of the gas increases |
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Charles's law |
the law taht sattes taht for a fixed amount of gas at a constant pressure the volume ofthe gas increases as teh temperature of the ags increases and the volume of the gas decreases as the temperature of the gas decreases |
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Gay-Lussac's law |
the law taht states taht the pressure of a gas at a constant volume is directly proportional to the absolute temperature |
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nucleus |
an atom's central region which is made up of protons and neutrons |
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proton |
a subatomic particle that has a positive charge and that is found in the nucleus of an atom |
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neutron |
a subatomic particle that has no charge and taht is found in the nucleus of an atom |
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electron |
a subatomic particle that has a negative charge |
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orbital |
a region in an atom wehre there is a high probability of finding electrons |
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valence electron |
an electron that is found in the outermost shell of an atom and taht determines the atom's chemical properties |
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periodic law |
the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements |
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period |
a horizontal row of elements in the periodic table |
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group (family) |
a vertical column of elements in the periodic table |
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ion |
an atom or group of atoms taht has lost or gained one or more electrons adn has a negative or positive charge |
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atomic number |
the number of protons in the nucleus of an atom |
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mass number |
the sum of the numbers of protons and neutrons in the nucleus of an atom |
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isotope |
an atom that has the same number of protons as other atoms of the same element do but taht has a different number of neutrons |
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atomic mass unit (amu) |
a unit of mass that describes the mass of an atom or moleule; it is exactly one-twelfth of the mass of a carbon atom with mass number 12 |
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average atomic mass |
the weighted average of the masses of all naturally occurring isotopes of an element |
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branches of science |
science: natural & social; natural: life, physical, & earth; life: biology, zoology, atonomy, & ecology; physical: physics & chemistry; earth: geology & meteorology |
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scientific method |
1. observe 2. ask a question 3. research and collect data 4. form a hypothesis 5. test the hypothesis 6. observe 7. conclusions |
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meter |
length |
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kilogram |
mass |
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seconds |
time |
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kelvin |
temperature |
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mole |
amount |
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candela |
luminosity |
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ampere, amps |
electric current |
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kilo |
1000 |
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mega |
1000000 |
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giga |
1000000000 |
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deci |
0.1 |
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centi |
0.01 |
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milli |
0.001 |
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micro |
0.000001 |
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nano |
0.000000001 |
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heterogeneous mixture |
substances aren't mixed uniformly and are not evenly distributed |
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homogeneous mixture |
components are evenly distributed and the mixture is the same throughout |
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physical properties |
shape, color, odor, texture, melting point, boiling point, strength, hardness, and ability to conduct electricity, magnetism, or heat, and can be measured are examples of... |
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chemical properties |
describes how a substance changes into a new substance, either by combining with other elements or by breaking apart into new substances, includes reactivity and flammability |
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density |
mass/volume |
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kinetic theory of matter |
all matter is made of atoms and molecules that act like tiny particles, these particles are always in motion and the higher the temperature of a substance the faster the particles move, and at the same temperature more massive particles move slower than less massive particles |
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solid |
particles are compact, definite shape and volume |
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liquids |
particles move more freely, no definite shape but definite volume |
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gases |
particles move freely and fill their containers, no definite shape or volume |
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plasma |
same properties as gas but reacts with electricity |
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endothermic |
taking in energy/heat |
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exothermic |
giving off energy/heat |
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pressure |
force/area |
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Boyle's law |
P1V1 = P2V2 |
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