Chapter 2 Flashcards
Negatively charged ion
Anion
The smallest unit of matter that retains the properties of an element.
Atom
The total mass of an atom, numerically equivalent to the mass in grams of 1 mole of the atom.
Atomic mass
An atom’s dense central core, containing protons and neutrons.
Atomic nucleus
The number of protons in the nucleus of an atom, unique for each element and designated by a subscript.
Atomic number
Positively charged ion
Cation
An attraction between two atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells.
Chemical bond
In a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of the reactants and products do not change with time.
Chemical equilibrium
The making and breaking of chemical bonds, leading to changes in the composition of matter.
Chemical reaction
A substance consisting of two or more different elements combined in a fixed ratio.
Compound
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons.
Covalent bond
A measure of mass for atoms and subatomic particles; the same as the atomic mass unit, or amu.
Dalton
the sharing of two pairs of valence electrons by two atoms.
Double bond
A subatomic particle with a single negative electrical charge and a mass about 1/2,000 that of a neutron or proton.
Electron
The attraction of a given atom for the electrons of a covalent bond.
Electronegativity
An energy level of electrons at a characteristic average distance from the nucleus of an atom.
Electron shell
Any substance that cannot be broken down to any other substance by chemical reactions.
Element
The capacity to cause change, especially to do work (to move matter against an opposing force).
Energy
A chemical element required for an organism to survive, grow, and reproduce.
Essential element
The amount of time it takes for 50% of a sample of a radioactive isotope to decay.
Half-life
A type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule.
Hydrogen bond
An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge.
Ion
A chemical bond resulting from the attraction between oppositely charged ions.
Ionic bond
A compound resulting from the formation of an ionic bond; also called a salt.
Ionic compound
One of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass.
Isotope
The total number of protons and neutrons in an atom’s nucleus.
Mass number
Anything that takes up space and has mass.
Matter
Two or more atoms held together by covalent bonds.
Molecule
A subatomic particle having no electrical charge (electrically neutral), with a mass of about 1.7 x 10−24g, found in the nucleus of an atom.
Neutron
A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity.
Non polar covalent bond
The three-dimensional space where an electron is found 90% of the time.
Orbital
A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.
Polar covalent bond
The energy that matter possesses as a result of its location or spatial arrangement (structure).
Potential energy
A material resulting from a chemical reaction.
Product
A subatomic particle with a single positive electrical charge, with a mass of about 1.7 x 10−24g, found in the nucleus of an atom.
Proton
An isotope (an atomic form of a chemical element) that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy.
Radioactive isotope
A method for determining the absolute age of rocks and fossils, based on the half-life of radioactive isotopes.
Radiometric dating
A starting material in a chemical reaction.
Reactant
A compound resulting from the formation of an ionic bond; also called an ionic compound.
Salt
the sharing of a pair of valence electrons by two atoms.
Single bond
An element indispensable for life but required in extremely minute amounts.
Trace element
The bonding capacity of a given atom; the number of covalent bonds that an atom can form, which usually equals the number of unpaired electrons in its outermost (valence) shell.
Valence
An electron in the outermost electron shell.
Valence electron
The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom.
Valence shell
Weak attractions between molecules or parts of molecules that result from transient local partial charges.
Van der waals interactions
