Atoms of the same element that have different numbers of neutrons and thus different mass numbers.

An enzyme that differs in amino acid sequence but catalyzes the same chemical reaction as another enzyme.

A disease that recurs repeatedly or follows a cyclic pattern.

Immune thrombocytopenic purpura, a disorder causing low platelet counts and increased bleeding risk.

Symbol for joule, the SI unit of energy; also used as a variable in equations.

Also called the vomeronasal organ, a chemoreceptor organ used in detecting pheromones.

A hybrid animal resulting from the cross between a male jaguar and a female lion.

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

A chemical bond formed between two ions with opposite charges.

A compound composed of positively and negatively charged ions held together by ionic bonds.