CHAPTER 1: INTRODUCTION TO CHEMISTRY
Hypothesis: A
general statement about the relationship between a manipulated variable and a responding
variable in order to explain an event or phenomenon.
Fixed
Variable: The factor that is kept constant throughout an
experiment.
Manipulated
Variable: The factor that is purposely changed in an experiment.
Responding
Variable: The factor that changes with the manipulated variable.
CHAPTER 2: THE STRUCTURE OF THE ATOM
Atom: The
atom is the smallest part of matter that represents a particular element.
Atomic
Number: The number of protons in a particular atom.
Atomic
Weight: The weight in grams of one mole of the chemical element;
approximately the number of protons and neutrons in the nucleus.
Boiling:
The
process by which a substance moves from the liquid state to the gaseous state
is called boiling. The temperature at which a liquid begins to boil is called
the boiling point (bp). The temperature of a boiling substance remains constant
until all of it has been converted to a gas.
Compound: A
compound is composed of two or more elements in a specific ratio.
Condensation: Transformation
from a gas to a liquid.
Deposition: The
process by which water changes phase directly from vapor into a solid without first
becoming a liquid. (Solidification of
vapors by cooling; the opposite of SUBLIMATION).
Diffusion: The
movement of particles of a substance in between the particles of another
substance. Diffusion occurs slowest in solids, faster in liquids and the
fastest in gases.
Electron: A
light subatomic particle with negative charge; found in orbitals surrounding an
atomic nucleus.
Element: An
element is composed of a single kind of atom.
Freezing: To
solidify a liquid by removal of heat.
Gas: A
gas has no definite shape and no definite volume. In a gas, particles are much
farther apart than they are in solids or liquids and they’re moving relatively
independent of each other.
Ion: An
Ion is a positively (+) or negatively (-) charged particles.
Isotopes:
Isotopes are atoms of the same element with the same number of protons but
different numbers of neutrons.
Liquid:
Liquids have no definite shape; however, they do have a definite volume, just
like solids do. The particles in liquids are much farther apart than the
particles in solids, and they’re also moving around much more.
Mass
Number: The sum of the number of protons plus the number of
neutrons in an atom is called the mass number. [Proton Numbers + Neutron
numbers = Mass Number]. The mass number (also called the atomic weight) is
listed in amu.
Matter:
Matter is anything that has mass and occupies space. It can exist in one of
three classic states: solid, liquid, and gas.
Melting: The
solid begins to go from a solid state to a liquid state a process called
melting. The temperature at which melting occurs is called the melting point
(mp) of the substance. The melting point for ice is 32°F, or 0°C.
Mixtures:
Mixtures are physical combinations of pure substances that have no definite or
constant composition.
Molecule: A
molecule is a combination of 2 or more atoms which are chemically bonded
together.
Nucleon
Number: Nucleon Number is the total number of protons and
neutrons in the nucleus of an atom.
Nucleon Number = Mass Number = Atomic Weight
Proton
Number: Proton Number is the number of protons in the nucleus of
an atom.
Sublimation: The
direct vaporization or transition of a solid directly to a vapor without
passing through the liquid state.
Solid: A
solid has a definite shape and occupies a definite volume. The particles that
make up the solid are very close together and aren’t moving around very much.
That’s because in many solids, the particles are pulled into a rigid, organized
structure of repeating patterns called a crystal lattice.
Valence
Electrons: Valence Electrons are electrons found in the outermost
occupied shell of an atom.
CHAPTER 3: CHEMICAL FORMULAE AND EQUATIONS
Avogadro’s
number: 6.02 × 1023, the number of molecules in 1
mole of a substance.
Chemical
equation: A representation of a chemical reaction in words or
using chemical formulae.
Chemical
formula: A representation of a compound to show its composition
using symbols and subscript numbers.
Empirical
formula: A chemical formula that shows the simplest whole number
ratio of atoms of each element in a compound.
Mole: An
amount of a substance equal in grams to the sum of the atomic weights.
Molecular
formula: Describes the ratio of elements in a molecule.
Molality: The
number of moles of solute in 1 kilogram of solvent.
Molarity: The
number of moles of solute in 1 liter of solution.
CHAPTER 4: PERIODIC TABLE OF ELEMENTS
Alkali
metals: Elements in Group 1 of the Periodic Table, which include
lithium, sodium, potassium, rubidium, caesium and francium.
Alkaline
earths metals: The
column of elements from beryllium to radium (Group 2) of the Periodic Table.
Electropositive:
Pertaining to elements, ions, or radicals that tend to give up or lose
electrons.
Electronegative:
Pertaining to an atom or group of atoms that has a relatively great tendency to
attract electrons to itself.
Ductile: Easily
drawn out into wire.
Halogen:
Elements in Group 17 of the Periodic Table, which include fluorine, chlorine,
bromine, iodine and astatine.
Group: A
vertical column of elements in the Periodic Table.
Inert
Gas:
The column of elements from helium to radon (Group 18) of the Periodic Table;
also called noble gases.
Malleable: Easily
shaped.
Metals: The
elements in the middle and left parts of the periodic table, except for
hydrogen.
Metalloids: They
have properties between those of metals and nonmetals.
Nonmetals: The elements in the upper right part of the
periodic table, and also hydrogen.
Octet
Rule:
A principle that bonded atoms have eight outer electrons (including those
shared with other atoms), although there are exceptions.
Period: A
horizontal row of elements in the Periodic Table.
Periodic
table: Periodic table display of the elements in order of
atomic number with similar elements falling into columns.
Transition
Elements: Elements in Group 3 to Group 12 of the Periodic Table.
CHAPTER 5: CHEMICAL BONDS
Ionic
bonds: A type of chemical bonding in which one or more
electrons are transferred completely from one atom to another, thus converting
the neutral atoms into electrically charged ions; these ions are approximately
spherical and attract one another because of their opposite charge.
Ionic
compound: A compound that consists of positive ions and negative
ions arranged in the crystal lattice and are attracted to each other by strong
electrostatic forces.
Covalent
bonds: A bond in which each atom of a bound pair contributes
one electron to form a pair of electrons.
Covalent
compounds: Atoms linked together by sharing valence electrons.
Melting
Point: The temperature at which a solid turns a liquid at a
fixed pressure.
Boiling
Point: The temperature at which a liquid changes to a gas.
CHAPTER 6: ELECTROCHEMISTRY
Anion: A
negatively-charged ion.
Anode: An
electrode which is connected to the positive terminal of the source of
electricity during electrolysis.
Aqueous
solution: A solution produced when a compound is dissolved in
water.
Cation: A
positively-charged ion.
Cathode: An
electrode which is connected to the negative terminal of the source of
electricity during electrolysis.
Displacement
reactions: A reaction where a more electropositive metal displace
another metal from its salt solution.
Electrochemical
series: A list of ions arranged in ascending order of their
tendency to donate electrons.
Electrochemistry: Electrochemistry
is an area of chemistry in which we use chemical reactions to produce electrons
or use electrons (electricity) to cause a desired chemical reaction to take
place.
Electrode: A
conductor in the form of wire, rod or plate which carry electric current in and
out of an electrolyte during electrolysis.
Electrolysis: The
process whereby a compound is broken down into its constituent elements when
electricity is passed through an electrolyte.
Electrolyte: A
substance that can conduct electricity in molten state or aqueous solution and
is decomposed by electric current.
Electronegativity: Electronegativity is a measure of the
tendency of an atom to attract a bonding pair of electrons.
Electroplating
of metals: The process of coating a layer of metal onto another
metal using electrolysis.
Electropositivity:
A
measurement of the ability of an atom to donate electrons to form a positive
ion.
Non-electrolyte: A
substance that cannot conduct electricity in molten state or aqueous solution.
Purification
of metals: The process of obtaining a pure metal from an impure
metal through electrolysis.
Simple
Voltaic Cells: A cell that converts chemical energy into
electrical energy.
CHAPTER 7: ACIDS AND BASES
Acid:
A
chemical substances which ionizes in water to produce hydrogen ions.
Alkali:
A
chemical substances which ionizes in water to produce hydroxide ions; synonym
for base.
Acid-base
titration: A quantitative analysis to determine the volume of an
acid required to exactly neutralize a fixed volume of an alkali with the help
of a suitable indicator.
End
point: A stage achieved in titration where the volume of acid
added exactly neutralizes a fixed volume of an alkali.
Molality: The
number of moles of solute in 1 kilogram of solvent.
Molarity: The
number of moles of solute in 1 dm3 solution.
Neutralization:
A
reaction between an acid and an alkali or a base to produce salt and water.
pH: A
number describing the concentration of hydrogen ions in a solution. Equals –log
[H+].
Titration: A method in which one
solution is added to another until the reaction between the two is complete.
CHAPTER 8: SALTS
Salt: An
ionic compound formed when the hydrogen ion in an acid is replaced by a metal
ion or an ammonium ion.
Recrystallization: A
technique used to purify crystals of a soluble salt by carrying out the crystallization
process again on these crystals.
Precipitation
reaction: A reaction which involves the reaction between two
aqueous reactants to form an insoluble substance.
Continuous
variation method: An experiment which involves the reaction of
a solution at fixed volume and another solution which volumes that vary
uniformly.
CHAPTER 9: MANUFACTURED SUBSTANCES IN INDUSTRY
Alloy: A
mixture of two or more elements with certain fixed composition in which the
major component is a metal.
Ammonium
fertilizer: A salt that is prepared from the reaction between
ammonia and an acid.
Ceramics: Formed of clay
(aluminosilicates), in whole or in part, and baked; also used to describe other
refractory materials, such as oxides and nitrides, with network structures.
Composite
materials: A composite material is made by combining two or more
materials – often ones that have very different properties.
Contact
process: A method in which sulfur trioxide and sulfuric acid are
produced from sulfur dioxide.
Glass:
Glass
is an amorphous (non-crystalline) solid material which is often transparent and
has widespread practical, technological, and decorative usage in things like
window panes, tableware, and optoelectronics.
Haber
process: An industrial process for the catalyzed production of
ammonia from N2 and H2 at high temperature and pressure.
Metal
corrosion: The gradual destruction of a metal by reaction with its
environment.
Polymer: A
macromolecule of high relative molecular mass composed of many similar or
identical monomers linked together in chains.
Synthetic
polymers: Synthetic polymers are polymers made in the industry from
chemical substances.
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