Chemistry Vocab Flashcards
(27 cards)
The weighted average of the masses of the isotopes of an element
Atomic mass
The smallest particle of an element that retains its identity in a chemical reaction
Atom
The number of protons in the nucleus of an atom of an element
Atomic number
Water that contains dissolved substances
Aqueous solution
A substance that contains two or more elements chemically combines in a fixed proportion
Compound
The ability of a substance to undergo a specify chemical change
Chemical property
A substance that increases the rate of reaction by lowering the activation-energy barrier; the _______ is not used up in the reaction
Catalyst
An expression that indicates the number and type of atoms present in the smallest representative unit of a substance.
Chemical formula
An expression representing a chemical reaction; formulas of the reactants are connected by an arrow with the formulas for the products
Chemical equation
A bond process by which hydrocarbons are broken down or rearranged into smaller, more useful molecules
Covalent bond
The ratio of the mass of an object to its volume
Density
A notation the depicts valence electrons as dots around the atomic symbol of the element; the symbol represents the inner electrons and atomic nucleus; also called Lewis dot structure
Electron dot structure
The simplest form of matter that has a unique set of properties; an element cannot be broken down into simpler substance by chemical means
Element
The lowest whole-number ratio of ions in an ionic compound; in magnesium chloride, the ratio of magnesium ions to chloride ions is 1:2 and the _____ ___ is MgCl2
Formula unit
A vertical column of elements in the periodic table; the constituent elements of a group have similar chemical and physical properties
Group (periodic table)
A molecule consisting of two atoms
Diatomic molecule
A mixture that is not uniform in composition, components are not evenly distributed throughout the mixture
Heterogeneous mixture
A mixture that is uniform in composition; components evenly distributed and not easily distinguished
Homogenous mixture
A nonmetal in Group 7A of the periodic table
Halogen
An atom or group of atoms that has a positive or negative charge
Ion
Atoms of the same element that have the same atomic number but different atomic masses due to a different number of neutrons
Isotopes
A compound composed of positive and negative ions
Ionic compound
Anything that has mass and occupies space
Matter
A neutral group of atoms joined together by covalent bonds
Molecule
