Term | Definition |
Accuracy | How closely a measurement aligns with a correct value |
Atom | Smallest particle of an element that can enter into a chemical combination |
Celsius | Unit of temperature; water freezes at 0 degrees Celsius and boils at 100 degrees Celsius on this scale |
Chemical Changes | Change producing a different kind of matter from the original kind of matter |
Change Property | Behavior that is related to the change of one kind of matter into another kind of matter |
Chemistry | Study of the composition, properties, and interactions of matter |
Compound | Pure substance that can be decomposed into two or more elements |
Cubic Centimeter | Volume of a cube with an edge length of exactly one centimeter |
Cubic Meter | SI unit of volume |
Density | Ratio of mass to volume for a substance or object |
Dimensional Analysis | Versatile mathematical approach that can be applied to computations ranging from simple unit conversions to more complex, multi-step calculations involving several different quantities |
Elements | Substance that is composed of a single type of atom; a substance that cannot be decomposed by a chemical change |
Exact Number | Number derived by counting or by definition |
Extensive Property | Property of a substance that depends on the amount of the substance |
Fahrenheit | Unit of temperature; water freezes at 32 degrees Fahrenheit and boils at 212 degrees Fahrenheit on this scale |
Gas | State in which matter has neither definite volume nor shape |
Heterogeneous Mixture | Combination of substances with a composition that varies from point to point |
Homogeneous Mixture | (Also, solution) combination of substances with a composition that is uniform throughout |
Hypothesis | Tentative explanation of observations that acts as a guide for gathering and checking information |
Intensive Property | Property of a substance that is independent of the amount of the substance |
Kelvin (K) | SI unit of temperature; 273.15 K = 0 degrees Celsius |
Kilograms (kg) | Standard SI unit of mass; 1 kg = approximately 2.2 pounds |
Law | Statement that summarizes a vast number of experimental observations, and describes or predicts some aspect of the natural world |
Law of Conservation of Matter | When matter converts from one type to another or changes form, there is no detectable change in the total amount of matter present |
Length | Measure of one dimension of an object |
Liquid | State of matter that has a definite volume but indefinite shape |
Liter (L) | (Also, cubic decimeter) unit of volume; 1 L = 1000 cm cubed |
Macroscopic Domain | Realm of everyday things that are large enough to sense directly by human sight and touch |
Mass | Fundamental property indicating amount of matter |
Matter | Anything that occupies space and has mass |
Meter (m) | Standard metric and SI unit of length; 1 m = approximately 1.094 yards |
Microscopic Domain | Realm of things that are much too small to be sensed directly |
Milliliter (mL) | 1/1000 of a liter = 1 cm cubed |
Mixture | Matter that can be separated into its components by physical means |
Molecule | Bonded collection of two or more atoms of the same or different elements |
Physical Change | Change in the state or properties of matter that does not involve a change in its chemical composition |
Physical Property | Characteristic of matter that is not associated with any change in its chemical composition |
Plasma | Gaseous state of matter containing a large number of electrically charged atoms and/or molecules |
Precision | How closely a measurement matches the same measurement when repeated |
Pure Substance | Homogenous substance that has a constant composition |
Rounding | Procedure used to ensure that calculated results properly reflect the uncertainty in the measurements used in the calculation |
Scientific Method | Path of discovery that leads from question and observation to law or hypothesis to theory, combined with experimental verification of the hypothesis and any necessary modification of the theory |
Second (s) | SI unit of time |
SI Units (International System of Units) | Standards fixed by the international agreement in the International System of Units |
Significant Figures | (Also, significant digits) all of the measured digits in a determination, including the uncertain last digit |
Solid | State of matter that is rigid, has a definite shape, and has a fairly constant volume |
Symbolic Domain | Specialized language used to represent components of the macroscopic and microscopic domains, such as chemical symbols, chemical formulas, chemical equations, graphs, drawings, and calculations |
Theory | Well-substantiated, comprehensive, testable explanation of a particular aspect of nature |
Uncertainty | Estimate of amount by which measurement differs from true value |
Unit | Standard of comparison for measurements |
Unit Conversion Factor | Ratio of equivalent quantities expressed with different units; used to convert from one unit to a different unit |
Volume | Amount of space occupied by an object |
Weight | Force that gravity exerts on an object |
Chemistry today... | continues to deepen our understanding and improve our ability to harness and control the behavior of matter |
What is chemistry considered? | Considered a central science due to its connections with other approaches of STEM |
What is chemistry based on? | Chemistry is based on observation and experimentation; involves answering questions and explaining observations through laws and theories of chemistry |
How do you test hypotheses? | through experimentation, calculation, and/or comparison with other experiments |
What do hypotheses attempt to explain? | Hypotheses attempt to explain the laws of science |
What are the 3 domains to study/describe matter and energy? | Macroscopic, microscopic, and symbolic |
How are solids and liquids matter? | Solids and liquids are observed taking up space and has mass |
How is gas a matter? | Gas is matter because without it, a balloon would stay collapsed |
Solids are... | rigid with a definite shape |
Liquids... | flow and takes shape of container |
What forms when liquid is acted upon by gravity? | Liquid forms a flat or slightly curved upper surface when acted upon by gravity |
What happens to liquids in zero G? | Liquids assume a spherical shape |
What are liquids and solids nearly independent of? | Pressure |
Gas... | takes both shape and volume of container |
What is the 4th state of matter? | Plasma |
What does plasma occur naturally? | Naturally occurs inside stars |
Plasma... | is a gaseous state with appreciable numbers of electrically charged particles |
How is plasma distinct from gas? | Plasma is distinct from gas due to electrically charged particles |
What are some examples of where plasma is found? | Plasma is found in lightning, certain tv screens, and instruments that detect metals |
What are the two ways to measure mass? | 1. measure force to accelerate and 2. compare mass to standard mass with a balance |
Is weight related to mass? | Weight is related to mass but it is not the same thing |
What is force proportional to? | force is proportional to mass |
What is true about weight, force, and mass? | Weight changes as force of gravity changes but mass stays the same |
What is an easier explanation on the law of conservation of matter? | matter can neither be created nor destroyed |
Who first suggested that matter is composed of atoms? | Greek philosophers Leucippus and Democritus during 5th century BCE |
Who supported the theory of Leucippus and Democritus? | In the 19th century, John Dalton the hypothesis with quantitative measurements |
What is the bond between atoms that makes a molecule? | A chemical bond |
How do atoms move around in a molecule? | Atoms move around as a unit; six-pack can of soda, keys in a key ring, and water |
What are the two broad categories of matter? | Mixtures and pure substances |
What do all specimens of pure substances have? | All specimens of pure substances have exactly the same makeup and properties |
Pure substances can be divided into... | elements and compounds |
What can compounds produce? | Either elements or other compounds or both |
What are the two types of mixtures? | Heterogeneous mixture and homogenous mixture |
What is an example of a mixture? | Evaporation |
What is an example of a heterogeneous mixture? | Italian dressing |
What is an example of a homogenous mixture? | Sports drinks have same amounts of water, sugar, coloring, flavoring, electrolyte mixed together uniformly |
What is true about the elements? | Over 100 elements with tens of millions of combinations; each has specific composition and possesses definite chemical and physical properties |
What are properties? | characteristics enabling us to distinguish one substance from another |
What are the physical properties? | Density, color, hardness, melting/boiling point, electrical conductivity; some physical properties are observed without changing the physical state |
What are some examples of physical change? | wax melting, sugar dissolving, and steam condensing to water; still the same chemical composition but different physical state |
What is an easier definition of chemical property? | change of one type of matter into another type; example include flammability, toxicity, acidity, reactivity, heat of combustion |
How do we identify chemical properties? | To identify chemical property, look 4 chemical change |
Simple definition of extensive property? | Property depending on the amount of matter present; mass and volume of substance; |
Example of both extensive and intensive property? | Both a drop of hot cooking oil and pot of oil are at the same temperature (intensive), but pot clearly contains much more heat (extensive) |
What are the 3 classes of the elements based on their properties? | Properties can be used to sort the elements in 3 classes: metals, nonmetals, and metalloids |
Metals... | conduct well |
Nonmetals... | conduct poorly |
Metalloids... | have properties of both metals and nonmetals |
What do measurements provide? | Measurements provide macroscopic information, which is the basis of most hypotheses, theories, and laws |
What type of information do measurements provide? | Measurements provide 3 kinds of information: numbers, units, and indication of uncertainty |
The numbers in measurements... | are represented through decimal form and scientific notation; 298,000 kg = 2.98 x 10 to the 5th power kg |
The units in measurements... | are standards of comparison for measurements (L, lb, m); without units, numbers can be confusing |
What is the unit for length? | meter (m) |
What is the unit for mass? | kilogram (kg) |
What is the unit for time? | second (s) |
What is the unit for temperature? | kelvin (k) |
What is the unit for electric current? | ampere (A) |
What is the unit for amount of substance? | mole (mol) |
What is the unit for luminous intensity? | candela (cd) |
femto... | f; factor of 10 to the -15 |
pico... | p; factor of 10 to the -12 |
nano... | n; factor of 10 to the -9 |
micro... | μ; factor of 10 to the -6 |
milli... | m; factor of 10 to the -3 |
centi... | c; factor of 10 to the -2 |
deci... | d; factor of 10 to the -1 |
kilo... | k; factor of 10 to the third |
mega... | M; factor of 10 to the sixth |
giga... | G; factor of 10 to the ninth |
tera | T; factor of 10 to the twelfth |
Where were the initial units of the metric system established? | The initial units of the metric system was established in France during the French Revolution; eventually became SI |
What is the standard unit of length for SI and original metric system? | The standard unit of length for SI and original metric system is the meter (m) |
How many inches are in a meter? | 39.37 inches |
How many yards are in a meter? | 1.094 yards |
How many meters are in a kilometer? | 1000 meters or 10 to the 3rd power |
How many meters are in a centimeter? | 0.01 meters or 10 to the -2 power |
How many meters are in a millimeter? | 0.001 meters or 10 to the -3 power |
How is a kilogram defined? | It is defined by a certain cylinder of platinum-iridium alloy, which is kept in France |
1 kilogram equals? | 2.2 pounds or 1000 grams or 10 to the -3rd power |
What property is temperature? | Temperature is an intensive property |
What other units of time can be used in the SI system? | hours, days, and years can be used |
What is the standard SI unit for volume? | The standard SI unit for volume is length; standard volume is cubic meter which is a cube with an edge length of a meter |
What is a more commonly used unit of volume? | A more commonly used unit of volume is decimeter (0.1 m or 10 cm) |
What is the more common name for cubic decimeter? | Liter is the more common name for cubic decimeter |
How many quarts are in a liter? | 1 liter equals 1.06 quarts |
What is the volume of a cube with an edge length of exactly 1 centimeter? | cubic centimeter |
A cubic centimeter is also called? | a milliliter; 1/1000 of a liter |
Density is defined by? | the base units of mass and length |
What is the often used unit for the density of a solid or liquid? | g/cm cubed |
What is the often used unit for the density of a gas? | g/L |
What is the range of density for most solids and liquids? | Most solids and liquids have density between 0.7g/cm cubed and 19g/cm cubed |
Volume, in the formula to find density, is found... | indirectly through length measurement |
What is the only type of measurement free from uncertainty? | Counting; numbers of defined quantities are also exact |
Quantities derived from measurements other than counting are uncertain to varying extends due to? | practical limits of measurement process used |
How should measurements with a graduated cylinder be made? | Measurements with graduated cylinder should be made below meniscus; can only make reasonable estimates; pointless to estimate to hundredths place due to tenths place being uncertain |
Which is significant between leading, captive, and trailing? | Captive and trailing 0´s are significant and leading 0´s are insignificant |
What are the 3 rules of rounding? | add/subtracting - least number of decimal places; multiplying/dividing - least number of sig figs; rule of #5 |
How are measurements precise? | Measurements are precise if yield very similar result if repeated the same way |
How are measurements accurate? | Measurements are accurate if yields result very close to true/accepted value |
What is an easier definition of both accurate and precise? | Precise values agree with each other; accurate values agree with a true value |
How many yards are in a meter? | 1 m = 1.0936 yd |
How many cm are in an inch? | 1 in. = 2.54 cm |
How many miles are in a kilometer? | 1 km = 0.62137 mi |
How many meters are in a mile? | 1 mi = 1609.3 m |
How many quarts are in a liter? | 1 L = 1.0567 qt |
How many liters are in a quart? | 1 qt = 0.94635 L |
How many L are in cubic feet? | 1 cubic feet = 28.317 L |
How many mL are in a tbsp? | 1 tbsp = 14.787 mL |
How many lbs are in a kg? | 1 kg = 2.2046 lb |
How many grams are in a lb? | 1 lb = 453.59 g |
How many grams are in 1 (avoirdupois) oz? | 1 (avoirdupois) oz = 28.349 g |
How many grams are in 1 (troy) oz? | 1 (troy) oz = 31.103 g |
What does temperature refer to? | Temperature refers to hotness/coldness |
What happens to most substances when temperature increases or decreases? | When temperature increases, most substances expand and when temperature decreases, most contract |
What is the freezing/boiling point of water in Celsius? | Freezing = 0 degrees; Boiling = 100 degrees |
What is the freezing/boiling point of water in Fahrenheit? | Freezing = 32 degrees; Boiling = 212 degrees |
What is the formula to find degrees Fahrenheit? | 9/5 x Temp. in degree Celsius + 32 |
What is the formula to find degrees Celsius? | 5/9 (Temp. in degrees Fahrenheit - 32) |
What is the freezing/boiling point of water in Kelvin? | Freezing = 273.15 K; Boiling = 372.15 K |
What is the formula to find Kelvin? | Temp. in degrees Celsius + 273.15 |
What is the formula to find degrees Celsius using Kelvin? | Temp. in Kelvin - 273.15 |