The number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol.
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.
In a reversible chemical reaction, the point at which the rate of the forward reaction equals the rate of the reverse reaction.
A process leading to chemical changes in matter; involves the making and/or breaking of chemical bonds
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons
A subatomic particle with a single negative charge. One or more electrons move around the nucleus of an atom.
An energy level represented as the distance of an electron from the nucleus of an atom
A type of weak chemical bond 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.
One of several atomic forms of an element, each containing a different number of neutrons and thus differing in atomic mass.
A type of molecular notation indicating only the quantity of the constituent atoms.
An electrically neutral particle (a particle having no electrical charge), found in the nucleus of an atom.
nonpolar covalent bond
A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity.
periodic table of the elements
A chart of the chemical elements, arranged in three rows, corresponding to the number of electron shells in their atoms.
polar covalent bond
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.
An isotope (an atomic form of a chemical element) that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy.
A type of molecular notation in which the constituent atoms are joined by lines representing covalent bonds.
The bonding capacity of an atom, generally equal to the number of unpaired electrons in the atom's outermost shell.
The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom
van der Waals interactions
Weak attractions between molecules or parts of molecules that are brought about by localized charge fluctuations.