42 terms

Chemistry: The Central Science Chapter 2


Terms in this set (...)

The smallest units of an element that can combine with other elements
Subatomic particles
Electron, neutron, proton
Cathode ray: Thomson
Radiation originating from negative electrode (the cathode) that is attracted by negatively charged plates; "discovery" of electron
Oil-drop experiment: Millikan
Small drops of oil, which pick up extra electrons, fall between two electrically charged plates. Voltage of plates affected their rates of fall, which was measured and recorded.
Spontaneous emission of radiation by atoms; gives further evidence that the atom has a substructure
Plum Pudding model: J. J. Thomson
Small electrons embedded in an overall positively charged sphere
Gold foil experiment: Rutherford
When a beam of alpha particles strikes gold foil, most pass straight through, but some are scattered; the reason for this is presence of a nucleus
Electronic charge
Magnitude of the charge of the electron (1.602*10^-19)
Atomic mass units (amu)
Used to measure mass of an atom
Used to measure dimensions of an atom
Atomic number
Number of protons in the nucleus of an atom; all atoms of a given element have the same atomic number
Mass number
Sum of the number of protons and neutrons
Atoms of same element that different in mass number/number of neutrons
Atomic weight
Average atomic mass; can be calculated by multiplying the atomic masses of various isotopes by their percent abundance and then adding them together
Mass spectrometer
Provides most direct and accurate means of experimentally measuring atomic (and molecular) weights
Metallic elements (metals) location on PT
Left and middle of Periodic Table
Nonmetallic elements (nonmetals) location on PT
Upper right side
Metalloids location on PT
Line separating metals and non-metals
Diatomic molecule
A molecule that contains two atoms
Chemical formula
Composition of a substance
Empirical formula
Relative numbers of atoms of each kind in a molecular substance (ex: C2H4 -> CH2)
Molecular formula
Actual numbers of each type of atom in a molecule
Charged particles that have gained or lost electrons
Positively charged ions (have lost electrons), metals
Negatively charged ions (have gained electrons), nonmetals
Ionic compounds
Electrically neutral combinations of cations and anions; so, usually contain both metallic and nonmetallic elements
Polyatomic ions
Atoms that are joined together but carry a net charge
Chemical nomenclature rules for cations
If can have more than one charge, the charge is written in roman numerals in parentheses -> Iron (II)
If formed from nonmetal atoms, their names end in -ium
Chemical nomenclature rules for anions
Monatomic anions are formed by replacing the ending of the name of the element with -ide -> H- is hydrIDE
Chemical nomenclature rules for polyatomic anions containing oxygen: An Example
ClO4- PERchlorATE (one more O atom than chlorate)
ClO3- ChlorATE ion (most common)
ClO2- ChlorITE ion (one O fewer than chlorate)
ClO- HYPOchlorITE ion (one O fewer than chlorite)
Polyatomic anions containing oxygen
Chemical nomenclature rules for oxyanions containing H+
Add a prefix to "hydrogen" or "dihydrogen"
Chemical nomenclature rules for ionic compounds
Put name of cation before name of anion (Al(NO3)2 -> aluminum nitrate)
Chemical nomenclature rules for acids
If ends with IDE, the acid ends with IC and begins with HYDRO
If ends in ATE, ends with IC
If ends in ITE, ends with OUS
Chemical nomenclature rules for binary molecular compounds
Greek prefixes are used to indicate the number of atoms of each element
Prefixes for binary molecular compounds
Mono - 1
Di - 2
Tri - 3
Tetra - 4
Penta - 5
Hexa - 6
Hepta - 7
Octa - 8
Nona - 9
Deca - 10
Dalton's Atomic Theory
1. Each element is composed of extremely small particles called atoms
2. All atoms of a given element are identical to one another in mass and other properties, and are different from atoms of all other elements
3. Atoms are neither created nor destroyed in chemical reactions
4. Compounds are formed when atoms of more than one element combine
Organic Chemistry definition
Study of compounds that contain carbon
Contain only carbon and hydrogen
Hydrocarbons in which each carbon atom is attached to four other atoms
A compound in which an H atom of a hydrocarbon is replaced by an OH (ends in -ol)