CHM 2045C Kotz6e Text
Chapter 1: Matter and Measurement
Key Terms
1.* Absolute
zero: the lowest temperature believed to be possible. It is defined to be zero kelvin and has a value on the Celsius scale of
-273.15E C.
2.* Accuracy:
the agreement of a measurement with the accepted value for the quantity.
3. Atom: the smallest particle of an
element that retains the characteristic chemical properties of that element.
4. Boiling point: the temperature at which
a liquid boils.
5. Chemical bond: an interaction between
two atoms that holds them together in a molecule, ionic crystal, or covalent
network.
6. Chemical change: a change that produces
one or more new substances.
7. Chemical formula: a listing of the
chemical symbols for the elements present in a compound and the relative number
of atoms of each element present (written as subscripts).
8. Chemical property: a characteristic of
a material that describes whether and sometimes how readily one material will
react with another material.
9. Chemical symbol: an abbreviation used
to represent an element.
10.* Density:
indicates how much matter is packed into a given space; mathematical it is
calculated by dividing the mass of a material by its volume (D = m/V).
11.* Dimensional
analysis: a technique that pays attention to the units in a
calculation. The units are treated like
factors that can be cancelled if the appear both in the numerator and
denominator of a calculation.
12. Ductility: the ability of a material to
drawn into wire.
13. Electric conductivity: a property that
indicates whether a material will conduct electricity and the extent to which
it can do so.
14. Extensive property: a property of a
substance that depends on the amount of the substance present.
15. Gas: the physical state of matter that
has neither a fixed volume nor a fixed shape – both the volume and shape of a
gas is determined by its container. The
volume of a gas varies with temperature and pressure.
16. Heterogeneous: not uniform throughout.
17. Homogeneous: uniform throughout.
18. Intensive property: a property of a
substance that does not depend on the amount of the substance present.
19. Ion: an electrically charged atom or
group of atoms.
20. Kinetic energy: the energy of motion.
21. Kinetic Molecular theory: a theory of
matter used to explain the properties of solids, liquids, and gases. This theory supposes that all matter consist
of extremely small particles (atoms, molecules, or ion) which are in constant
motion.
22. Liquid: the physical state of matter
with a volume that changes little as temperature and pressure change but that
has no definite shape of its own – a liquid takes on the shape of the portion
of the container that it fills.
23. Macroscopic: large-scale; the
macroscopic view in chemistry is the world in which we live and make observations.
24. Malleability: the ability of a material
to be deformed (bent).
25. Matter: anything that mass and takes up
space.
26. Melting point: the temperature at a which a solid melts.
27. Mixture: a material formed by
physically together to or more elements, two or more compounds, or a
combination of elements or compounds. A
mixture can be made using any relative amounts of the components. The components do not chemical bond to each other
in the mixture.
28. Molecule: the smallest particle found
in nature for those elements whose atoms chemically bond together to form small
discrete particles; also, the smallest discrete particle of a nonionic
compound.
29. Periodic table: a table that lists the
elements in order of increasing atomic number and places elements with similar
properties in the same vertical column.
Each box on the periodic table usually includes the symbol for an
element as well as other useful information about the element.
30. Physical change: a change in physical
properties; a physical change does not produce new substances.
31. Physical property: a characteristic of
a material that can be observed without changing the composition of a
substance.
32.* Precision:
indicates how well several determinations of the same quantity agree.
33. Pure substance: a material that has its
own set of unique properties and that cannot be separated into two or more
different species by and physical technique.
34.* Pyrometer:
a device used to measure temperature; it measures the wavelength of light
emitted from an object and relates that to the object’s temperature.
35. Qualitative observation: an observation
that does not involve measurements and numbers.
36. Quantitative observation: an
observation that involves numerical information.
37.* SI:
the Système International d’Unitès,
the modern incarnation of the metric system used in scientific work.
38.* Significant
figures: the digits in a measured quantity that are know exactly plus one
digit that has some uncertainty; in the answer to a calculation, one should
report only digits that are significant.
39. Solid: the physical state of matter
that has a rigid shape and a fixed volume that changes little as temperature
and pressure change.
40. Solubility: the amount of a material
that will dissolve in a given amount of another material
41. Solution: a homogeneous mixture in
which the components are evenly distributed in each other down to an atomic or
molecular scale.
42. Submicroscopic (particulate): the level
of matter dealing with atoms, molecules, and ions.
43.* Temperature:
a property that determines the direction of heat transfer; heat transfers from
something at a higher temperature to something at a lower temperature.
44.* Viscosity:
a measure of how easily a liquid flows; the more viscous a liquid is, the less
readily it flows.
* Key Terms which are introduced in Module 2 and will not be
tested in Module 1 Part K.