Chemistry
The study of the composition, structure and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes
Physical Properties
A characteristic that can be observed or measured without changing the identity of the substance
Chemical Properties
Relates to the ability of a substance to undergo changes that transform it into different substances
Precision
Describes the closeness or reproducibility of a set of measurements
Atom
The smallest unit of an element that maintains the chemical identity of that element; the building block of matter
Neutron
A neutral subatomic particle in the nucleus of every atom except simple hydrogen
Nucleus
Positively charged center of an atom containing protons and neutrons
Anion
An ion with a negative electrical charge
Homogenous
A mixture with uniform composition
Atomic Mass Unit
A unit of measurement used to measure the mass of atoms
Covalent Bond
The mutual sharing of one or more pairs of electrons between two atoms
Octet Rule
A rule stating that atoms lose, gain, or share electrons in order to have a full valence shell of 8 electrons
Mass Number
The sum of protons and neutrons in the nucleus of an atom
Avogadro’s Number
6.02 x 10^23
Chemical Changes
A change in which one or more substances are converted into different substances; a reaction
Physical Changes
A change in a substance that does not involve a change in the identity of the substance
Mass
A measure of the amount of matter in an object
Accuracy
The closeness of a value to the correct or accepted value of the quantity measured
Proton
A positively charged particle that is in the nucleus of an atom
Electron
A negatively charged particle that travels around the nucleus of an atom
Cation
An ion with a positive electrical charge
Metalloids
Share some properties of metals and some of nonmetals, some shiny and some dull, some malleable and some not, some ductile and some not, semiconductors of electric energy
Heterogenous
A mixture without uniform composition
Ionic Bonding
The outermost electrons of one atom are transferred permanently to another atom
Chemical Bond
The bond that holds atoms together in molecules
Atomic Number
The number determining where an element is arranged; equal to the number of protons
Mole
Equal to Avogadro’s Number