Chemistry Vocabulary
Terms
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- ionization energy group trend
- ionization energies decrease down a group
- accuracy
- closeness of measurements to the correct or accepted value of the quantity measured
- precision
- closeness of a set of measurements of the same quantity made in the same way
- periods
- horizontal rows of the periodic table
- plasma
- high-temperature physical state of matter in which atoms lose most of their electrons
- system
- a specific portion of matter in a given region of space that has been selected for studying during an experiment
- chemical equilibrium
- rate of the forward reaction equals the rate of the reverse reaction
- electronegativity group trend
- electronegativity tends to stay the same down a group
- mixture
- a blend of two or more kinds of matter, each of which retains its own identity and properties
- angular momentum quantum number
- indicates the shape of the orbital
- law of conservation of mass
- mass cannot be created nor destroyed during ordinary chemical reactions or physical changes
- reversible reaction
- chemical reaction in which the products can react to reform the reactants
- metal
- an element that is a good conductor of heat and electricity
- formula unit
- simplest collection of atoms from which an ionic compound's formula can be established
- limiting reactant
- reactant that limits the amount of the other reactant that can combine and the amount of product that can form in a chemical reaction
- chemical bond
- mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together
- dipole
- created by equal but opposite charges that are separated by a short distance
- compound
- a substance that can be broken down
- mole ratio
- conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction
- conversion factor
- ratio derived from the equality between two different units that can be used to convert from one unit to another
- bond energy
- energy required to break a chemical bond and form neutral isolated atoms
- element
- a pure substance that cannot be broken down
- hypothesis
- testable statement
- photon
- a particle of electromagnetic radiation having zero mass and carrying a quantum of energy
- magnetic quantum number
- indicates the orientation of an orbital around the nucleus
- electronegativity period trend
- electronegativity tends to increase across a period
- solution
- a homogeneous mixture
- nonmetal
- an element that is a poor conductor of heat and electricity
- heisenberg uncertainty principle
- it is impossible to determine simultaneously both the position and velocity of an electron or any other particle
- quantum
- minimum energy that can be lost or gained by an atom
- isotopes
- atoms of the same element that have different masses
- synthesis reaction
- two or more substances combine to form a new compound
- percentage error
- calculated by subtracting the accepted value from the experimental value, dividing the difference by the accepted value, then multiplying by 100
- electronegativity
- measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound
- atom
- the smallest unit of an element that maintains the identity of that element
- mass number
- protons plus neutrons that make up the nucleus of an isotope
- excited state
- a state in which an atom has a higher potential energy than it has in its ground state
- london dispersion forces
- intermolecular attractions resulting from the constant motion of electrons and the creation of instantaneous dipoles
- salt
- an ionic compound composed of a cation and an anion from an acid
- ionization energy period trend
- ionization energies increase across a period
- principal quantum number
- indicates the main energy level occupied by the electrons
- decomposition reaction
- a single compound undergoes a reaction that produces two or more simpler substances
- weight
- measure of gravitational pull on matter
- atomic radii group trend
- atomic radii increase down a group
- ground state
- lowest energy state of an atom
- chemical equation
- represents with symbols and formulas, the identities and relative molecular or molar amounts of the reactants and products in a chemical reaction
- covalent bonding
- bond that results from the sharing of electron pairs between two atoms
- photoelectric effect
- emission of electrons from a metal when light shines on the metal
- chemical property
- a substance's ability to undergo changes that transform it into a different substance
- groups
- vertical columns of the periodic table
- ionization
- any process that results in the formation of an ion
- wavelength
- distance between corresponding points on adjacent waves
- solid
- a substance with a definite shape and volume
- reaction stoichiometry
- involves the mass relationships between the reactants and products in a chemical reaction
- aufbau principle
- an electron occupies the lowest energy level that will recieve it
- nuclide
- a general term for a specific isotope of an element
- monoatomic ion
- an ion formed from a single atom
- quantity
- something that has magnitude, size, or amount
- electromagnetic radiation
- a form of energy that exhibits wavelike behavior as it travels through space
- ionic bonding
- chemical bonding that results from the electrical attraction between cations and anions
- matter
- anything that has a mass and takes up space
- physical change
- a change in a substance that does not involve a change in the identity of the substance
- atomic number
- number of protons of each atom in an element
- volume
- amount of space occupied by an object
- theory
- a broad generalization that explains a body of facts or phenomena
- ionization energy
- the energy required to remove one electron from a neutral atom of an element
- orbital
- a three dimensional region around the nucleus that indicates the probable location of an electron
- electron affinity
- energy change that occurs when an electron is acquired by a neutral atom
- molecular compound
- a chemical compound whose simplest units are molecules
- law of multiple proportions
- if two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers
- la chatelier's principle
- if a system at equilibrium is subjected to a stress, the equilibrium is shifted in the direction that tends to relieve the stress
- physical property
- a characteristic that can be observed or measured without changing the identity of the substance
- liquid
- a substance with an indefinite shape and a definite volume
- gas
- a substance with an indefinite shape and volume
- periodic law
- physical and chemical properties of the elements are periodic functions of their atomic numbers
- single-replacement reaction
- an element replaces a similar element in a compound
- density
- the ratio of mass to volume
- binary compounds
- compounds composed of two or more elements
- ion
- an atom or group of bonded atoms that has a positive or negative charge
- homogeneous
- uniform in composition
- mass
- a measure of the amount of matter
- pauli exclusion principle
- no two electrons in the same atom can have the same four quantum numbers
- electrolysis
- decomposition of a substance by an electric current
- molar mass
- mass of one mole of a pure substance
- coefficient
- a small, whole number that appears in front of a formular in a chemical equation
- hund's rule
- orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all the electrons in singly occupied orbitals must have the same spin state
- change of state
- a physical change of a substance from one state to another
- molecule
- neutral group of atoms that are held together by covalent bonds
- electromagnetic spectrum
- x-rays, ultraviolet, infrared, microwaves, and radio waves